Select New on the class module
Type MyNewClass as the new "Class Name"
Select MyClass as the "Based On" template
Modify the "Store In" by overtyping the current vcx name with the new name you want - MyClasses.vcx and click OK
The New Class opens up and you can modify it and/or save it.

MyNewClass is now saved in MyClasses.vcx and you are done!

Godfrey