>The problem with this approach is that the parameter name would appear in
>the object browser.
The parameter name will appear, but who will know the value you pass there?
Unfortunately I agree with Alexandre, you can't pass parameters to Init event of the COM object.
But you could do something like that:

DEFINE CLASS MainClass AS ... OLEPUBLIC
    oChildClass = NULL
    
   PROCEDURE CreateChildClass()
         LOCAL loChild AS MyChildClass
         loChild = CREATEOBJECT([MyChildClass])
         loChild.UniqueString = [IWantToPlayWithThis]
         this.oChildClass = loChild
   ENDPROC
   .......
ENDDEFINE


DEFINE CLASS MyChildClass AS .... OLEPUBLIC
    UniqueString = []

    PROCEDURE AnyMethodOrEventOfThisClass
         IF NOT this.UniqueString == [IWantToPlayWithThis]
            this.Release()
            RETURN NULL
         ENDIF
         ....
    ENDPROC
ENDDEFINE

(not tested)