Is there a way to assign a "tooltip" to a shape or inserted picture?

I have shapes/picture that have attached macros that run when clicked. I
would like to have a tooltip popup when the mouse hovers over that shape,
just like the tooltip text that appears when hovering over command buttons on
toolbars.

Maybe there is a way to frame clipart with some shape-object that will allow
this?

Anyideas?

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Regards,
John