Thank you for your post.
I am having difficulty understanding where the files are located. I'm assuming the FileMaker file is located on the DMZ zone and talking to a file somewhere in the COB Zone. Is that correct?
LDAP does not come into play with this scenario.
How are you passing the information from one server to the other? The script would probably iinclude an Import step to import the data from one file to the other.
Any other information you can provide would be helpful.