As a person who knows C++ very well,
what tips can you give a person who
is looking to write a programming or script language?
Don't do it. (or at least think long and hard before you do!)
If you're trying to write a scripting language to expose the methods/properties of some custom-written objects, it would be better to implement those in Java (or .NET/VB or all those icky Microsoftisms) and then use one of the Bean Scripting Framework languages as your scripting language. (with whatever the equivalent is on the Microsoft end.)