Minimize the VB form

[FuzzyLogic]

I calling a function of VB dll. from excel macro.

This shows a Non - Modal form.

Now, I want to minimize this form when excel is minimized
and reset it to normal when excel is restored.

I am having the reference of the Excel in the dll, from which I am able
to catch the events of the excel in the dll.

But I could not found any event which can show me the window state of
the excel is changed.

Any Suggestions...