Just use MS Access to add more tables or fields to tables. Offcourse depending on what you want to do, you have to write the code or make necessary changes to existing code. This is what we call MOD writing here. For this you have to know moderate level ASP, VBScript, ADO etc (to understand, change, add new ASP files ...).
Look at the MODs forum to see what people are doing.
If you just want to add new fields to the Profile database, there is one mode you can find there.