How do I link two different field lengths with the same data

Hi,
In Crystal Reports 8.5, I am linking one file to another but do not get report data. The reason is the fields I am using to link one string is 4 characters while the other is 6. Is there a way to get two fields containing the same data in different files but wth different field lengths to link. thank youBump. This post is old, but I'm needing to do basically the same thing. I've got Crystal Reports 11.

Thanks