i guess u cant check if *.BAD fiels exist and ftp teh same, together.

so u need to first try connecting to destination box and list all the *.BAD files (into an existing file in source box) from the destination directory, as below:

from source box:
========

ftp destination ip
user xxx
pswd ***
cd destination directory(where *.BAD files are kept)
ls -ltr sourcedir_filename.txt (this will list all the files in destination dir to an existing file in source box)
bye

now you have a file "sourcedir_filename.txt" in your source box which has names of all the files (including *.BAD files).

so now you have to check if any *.BAD file exist in the above file and if it does then ftp the same files back to destination box.

this might be a lengthy way of doing it but it will work fine
cya