Validation Library and the preservation of slashes

[eluser]jdgiotta[/eluser]
I'm using the Validation library to validate supplied log-in information.
Now part of the requirements for a user name is a domain which relates to a LDAP bind.
For example a user would supply:
foo\jsomebody

However, if the user doesn't supply a password, Validation will kick them back and say "Hey forgot a password". Unfortunately, the backslash is lost making it a pain for the user to re-enter and a great deal of back forth with validation and failed log-ins.

Now I could rework/extend Validation to preserve the slash, but is there a trick that isn't documented so I don't have to go any further if I can avoid it?