[^A-Za-z0-9:]
The above character class includes the characters you want, and
the '^' at the start negates them. So the above will match ONE
character that is not any of an upper or lower case a to z or a
colon. You could search on that and replace with nothing.
This is standard PCRE (Perl Compatible Regular Expression)
syntax, not unique to BBEdit.
HTH
--
- Bruce
_bruce__van_allen__santa_cruz__ca_