Need help fo finish Batch script?

Sure. Here's how to write a batch script to do what you need done (in Python): Save it as runMogrify.py

import os
import string
import fnmatch

source = "c:\\TEST\\import"
target = "c:\\TEST\\export"

def mogrify(parmSource, parmTarget):
    mkdirList = []
    copyList = []
    mogrifyList = []

    mkdirList.append('mkdir "' + parmTarget + '"')

    for dirpath, dirnames, filenames in os.walk (parmSource):
        # print dirpath, dirnames, filenames
        for (index,file) in enumerate(sorted(filenames)):
            if fnmatch.fnmatch(file.lower(), '*.jpg') or \
               fnmatch.fnmatch(file.lower(), '*.gif') or \
               fnmatch.fnmatch(file.lower(), '*.bmp'):
                sourceFDirPathFile = dirpath + "\\" + file

                targetFDirPath     = os.path.join (parmTarget, dirpath[1+len (parmSource):])
                targetADirPathFile = targetFDirPath + "\\" + str(index+1) + "a" + os.path.splitext(file)[1]
                targetBDirPathFile = targetFDirPath + "\\" + str(index+1) + "b" + os.path.splitext(file)[1]

                if 'mkdir "' + targetFDirPath + '"' not in mkdirList:
                    mkdirList.append('mkdir "' + targetFDirPath + '"')

                copyList.append('copy "' + sourceFDirPathFile + '" "' + targetADirPathFile + '"')
                copyList.append('copy "' + sourceFDirPathFile + '" "' + targetBDirPathFile + '"')

                mogrifyList.append('mogrify -resize 400x300 "' + targetADirPathFile + '"')
                mogrifyList.append('mogrify -resize 200x150 "' + targetBDirPathFile + '"')

    return mkdirList, copyList, mogrifyList

def main():
    mkdirList, copyList, mogrifyList = mogrify(source, target)

    f = open('RUNMOGRIFY.BAT', 'w')
    f.writelines( list("%s\n" % item for item in mkdirList  ) )
    f.writelines( list("%s\n" % item for item in copyList   ) )
    f.writelines( list("%s\n" % item for item in mogrifyList) )
    f.close()

if __name__=="__main__": main()

And, here's the resulting batch file (RUNMOGRIFY.BAT) after I ran the Python script above
on a test directory similar to yours:

mkdir "c:\TEST\export"
mkdir "c:\TEST\export\folder1"
mkdir "c:\TEST\export\folder2"
mkdir "c:\TEST\export\folder3"
copy "c:\TEST\import\folder1\a.jpg" "c:\TEST\export\folder1\1a.jpg"
copy "c:\TEST\import\folder1\a.jpg" "c:\TEST\export\folder1\1b.jpg"
copy "c:\TEST\import\folder1\b.jpg" "c:\TEST\export\folder1\2a.jpg"
copy "c:\TEST\import\folder1\b.jpg" "c:\TEST\export\folder1\2b.jpg"
copy "c:\TEST\import\folder1\c.jpg" "c:\TEST\export\folder1\3a.jpg"
copy "c:\TEST\import\folder1\c.jpg" "c:\TEST\export\folder1\3b.jpg"
copy "c:\TEST\import\folder2\a.jpg" "c:\TEST\export\folder2\1a.jpg"
copy "c:\TEST\import\folder2\a.jpg" "c:\TEST\export\folder2\1b.jpg"
copy "c:\TEST\import\folder2\b.jpg" "c:\TEST\export\folder2\2a.jpg"
copy "c:\TEST\import\folder2\b.jpg" "c:\TEST\export\folder2\2b.jpg"
copy "c:\TEST\import\folder2\c.jpg" "c:\TEST\export\folder2\3a.jpg"
copy "c:\TEST\import\folder2\c.jpg" "c:\TEST\export\folder2\3b.jpg"
copy "c:\TEST\import\folder3\a.jpg" "c:\TEST\export\folder3\1a.jpg"
copy "c:\TEST\import\folder3\a.jpg" "c:\TEST\export\folder3\1b.jpg"
copy "c:\TEST\import\folder3\b.jpg" "c:\TEST\export\folder3\2a.jpg"
copy "c:\TEST\import\folder3\b.jpg" "c:\TEST\export\folder3\2b.jpg"
copy "c:\TEST\import\folder3\c.jpg" "c:\TEST\export\folder3\3a.jpg"
copy "c:\TEST\import\folder3\c.jpg" "c:\TEST\export\folder3\3b.jpg"
mogrify -resize 400x300 "c:\TEST\export\folder1\1a.jpg"
mogrify -resize 200x150 "c:\TEST\export\folder1\1b.jpg"
mogrify -resize 400x300 "c:\TEST\export\folder1\2a.jpg"
mogrify -resize 200x150 "c:\TEST\export\folder1\2b.jpg"
mogrify -resize 400x300 "c:\TEST\export\folder1\3a.jpg"
mogrify -resize 200x150 "c:\TEST\export\folder1\3b.jpg"
mogrify -resize 400x300 "c:\TEST\export\folder2\1a.jpg"
mogrify -resize 200x150 "c:\TEST\export\folder2\1b.jpg"
mogrify -resize 400x300 "c:\TEST\export\folder2\2a.jpg"
mogrify -resize 200x150 "c:\TEST\export\folder2\2b.jpg"
mogrify -resize 400x300 "c:\TEST\export\folder2\3a.jpg"
mogrify -resize 200x150 "c:\TEST\export\folder2\3b.jpg"
mogrify -resize 400x300 "c:\TEST\export\folder3\1a.jpg"
mogrify -resize 200x150 "c:\TEST\export\folder3\1b.jpg"
mogrify -resize 400x300 "c:\TEST\export\folder3\2a.jpg"
mogrify -resize 200x150 "c:\TEST\export\folder3\2b.jpg"
mogrify -resize 400x300 "c:\TEST\export\folder3\3a.jpg"
mogrify -resize 200x150 "c:\TEST\export\folder3\3b.jpg"

Excuse me, perhaps I didn't completely understand your question; however, here are a couple Batch segments that may help you.

The first segment rename all folders existent in "import" to 1,2,3,etc and keep their original names in "name" vector. The process is easier if there is no left-zero in the numbers:

cd "C:\TEST\import"
set i=0
for /D %%d in (*) do (
   set /A i+=1
   ren %%d !i!
   set name[!i!]=%%d
)

Please note that you may process each 1,2,3,etc folders in "import" folder in the same FOR loop above using %%d for the name of the folder.

The second segment rename all folders in "export" to its original names stored by the first segment above:

cd "C:\TEST\export"
for /D %%i in (*) do (
   ren %%i !name[%%i]!
)

If you use these segments in your program, you must include the next command at beginning:

setlocal EnableDelayedExpansion

Post any additional question if you have any doubt.