I'm not entirely sure what you mean. Could you give an example, with an
appropriate "what do I do here" line at the bit you don't know?

Hi,

   I think, if I understand correctly, you are looking for the keyword
TypeOf  - but I may be mistaken - here is what I think you are asking and
how to solve it

Class A
   Public Sub ClassASub1()
   end sub
   Public ClassAInteger1 as Integer
end class
Class b
   Public Sub ClassBSub1(A as string)
   end sub
   Public ClassBBoolean1 as Boolean
End Class

Class Test
   Public Sub TestIt()
       dim Obj as Object
       'First set it to be an instance of class A;
       Obj = new A()

       if TypeOf Obj is A then
           CType(Obj, A).ClassASub1()
          end if
       'now set it to an instance of B
       Obj = new B()
       if typeOf(Obj) is B then
           CType(Obj, B).ClassBSub1()
       end if
   end sub
end class

Is that what you wanted to know - does this explain / answer the question or
have I got the wrong end of the stick?

Nick