[UPHPU] Regex help.

[Ash]

I have a database that has addresses in it. The only characters allowed 
are A-z 0-9 and ,()':.

The database also has other characters in it, but I want to delete all 
the characters that are not allowed (because they crash my program that 
prints the addresses to the printer.)

It's just a text file, so I could run sed on it, but how do you test for 
just those characters?

Thanks,

Ash