compare directories but ignore a string

In my project I have skins which are a directory name and its corresponding variable.

So I have on skin that is jrFanClub. and its files will contain variables like $jrFanClub_something.

These skins can be cloned to a different name eg: xxFanClub. which will then have its variables as $xxFanClub_something.

QUESTION: I want to run the compare tool against the two folders to see what has changed when either one has been updated externally.  I want to ignore the directory names from the compare system.

Currently: every file shows as being different because jrFanClub is different from xxFanClub.  Im not interested in those, what I want to know is what has actually changed in the surrounding context.

Is there a way to add 'xxFanClub' and 'jrFanClub' to an exclusion list so their differences are not returned?

The screenshot above shows the compare issue.  For me this difference is un-interesting because its an expected difference, just the variable name that corresponds to the skin its in.  The rest of the code is the same.