If anyone else replies with a direct answer, then ignore this response:
You can make any cell into a button. Let's use cell E10. Color its
background, put a border around it, and insert any comment in it.
The comment will respond to the MouseOver. In worksheet code, enter
something like:
Private Sub Worksheet_SelectionChange(ByVal Target As Range)
If Intersect(Target, Range("E10")) Is Nothing Then
Else
MsgBox ("Hi there")
Range("E11").Select
End If
End Sub
If you click on E10, it will behave like a button. I admit this approach is
a little silly, but if no one else responds.......