I doubt GoDaddy is the only hosting company that will have a problem with +
characters in filenames. (Side note: I can't quite decide whether "foo+bar.aspx" refers to a file called "foo+bar.aspx" or one called "foo bar.aspx", since +
is shorthand URL-encoding for space. Tomcat didn't interpret it that way, I'd have to read the rules again to figure it out...)
I'd revise the program so it doesn't use URLs like that, replace the +
with _
or some such. A bunch of renames plus some global search-and-replace ops should do it.
To support old bookmarks, it'll depend on where GoDaddy doesn't support the +
. If they let the request through to your server, then yes, a rewriting rule should let you accept foo+bar.aspx and have it issue a redirect to foo_bar.aspx. There's a rewriting module for IIS 7; syntax and such are discussed in this article (I have no idea how good it is). Claims to use JavaScript-style regexes, which makes life easy for us webbies.