I haven't tried any of them, but i believe some IDE's have regular expression builders.. googling for "activestate perl regular expression editor" led me to Visual Perl which is a complete Perl development environment plug-in for Visual Studio .NET and has a Regular Expression (Rx) toolkit for almost effortless creation and debugging of powerful regular expressions.

Other than that, if they're are to be totally isolated from code but still help with the patterns, there's probaly a decent amount of help they can be and you can do the actual perl implementation.. some thoughts:

• They can describe patterns in a pseudo-code manner. "Will have 2 letters followed by 6 digits and then either 'ABC' or 'XYZ'"
• They can provide lists of example strings that should match, and lists of example strings that should not match.
• you can start with the pseudo-code and introduce the basics from there so they can adopt things like \d, \D, \S and \s in their short-hand
• depending on how they learn, you can give more (greediness, quantifiers, etc).. maybe let them know at least that those and other things (look ahead/behinds) are possible so they can take that into account in the pseudo-code w/o knowing the real syntax.
• hopefully they can pick up enough from seeing how their english descriptions turn into patterns to speed along your development