Batch working in 32-bit XP but not 64

I am having an unusual problem with a series of batch files. I have a program that is started by calling a very long, complicated string of batch files and Perl scripts. On 32-bit XP this works just fine, but on 64-bit XP it does not.

On 64-bit I can see that it cannot find a couple of the files. It is saying "!COMMON_DIR! is not a recognized as an internal or external command, operable command or batch file." I am not sure which file is actually giving the error as there are around 40 batch files that I know of that it calls. Again this exact same string of files works with no problems on 32-bit.

I have been told that this does indeed work on 64-bit XP and that the problem lies with my computer. Any ideas would be greatly appreciated.