In reply to ethan_td:
You are going to need to show us a little code. What do you mean by "I don't seem to be able to access the clock signal"? You can't figure out the syntax, or you are getting a compiler error, or you are not seeing the value updated?
A couple of comments about your terminology. We recommend defining all classes in a package, and then importing the package where you need to use the class. There are good exceptions to this recommendation, and your case could be one of them, but I need to see what you are trying to do.
We do not recommend the use of program blocks at any time. See http://go.mentor.com/programblocks . Use a module instead.