Thanks Ovid.  
That looks like it should do the trick:
1 - send user to page=home if no param supplied with URL, yet provide error if illegal character or nonexistant urlist file.
2 - reject index.pl?page=aaaa, as well as index.pl?page=,aaa

I'll give it a shot.
    cheers,
    Don
    striving for Perl Adept
    (it's pronounced "why-bick")