Y2K Bug in CTOD Function - dBASE 4 Help

In dBase 4 for DOS, the problem line is this:

ctod(tran(right(trim(memo),6),"@R xx/xx/xx")) < mrtedate

set century is on.
mrtedate is the route date and is entered by the user when printing routes.

I want to use an iif statement so that if the last xx is between 95 and 99
inclusive, then a 20th century date is returned, else a 21st century date is
returned.

Can anyone give me some help with this?

Thanks,
Vernon