Do you have a design in mind?
Your best bet is scripting and most custom menus are done that way. Picture eventing is also an option, but you'd have to be pretty good with events and it is graphic heavy (IE - you'd need seperate pictures for everything - every word, all 10 digits, and you'd need to make your own backgrounds and control everything).
Unless you are a decent eventer and have a lot of time on your hands, you should look for a script. Check out the
Script Index and see if anything there appeals to you. If not, you can always try a request, but if you do that you should have a detailed mockup prepared in Paint (with appropriate proportions) and follow the
Script Request Template.