Give it a try this until you are waiting Ivan's special answer.
How about use LostFocus event. But need to activate cells to recall the commandbutton's original backcolor.
<PRE><FONT color=red>Option Explicit</FONT>
<FONT color=red>Private <FONT color=red>Sub </FONT></FONT>CommandButton1_MouseMove(<FONT color=red>ByVal</FONT> Button <FONT color=red>As</FONT><FONT color=red> Integer</FONT>, _
<FONT color=red>ByVal</FONT> Shift <FONT color=red>As</FONT><FONT color=red> Integer</FONT>, _
<FONT color=red>ByVal</FONT> X <FONT color=red>As</FONT><FONT color=red> Single</FONT>, _
<FONT color=red>ByVal</FONT> Y <FONT color=red>As</FONT><FONT color=red> Single</FONT>)
CommandButton1.BackColor = &HFFFF&
CommandButton1.Activate
<FONT color=red>End Sub</FONT>
<FONT color=red>Private <FONT color=red>Sub </FONT></FONT>CommandButton1_LostFocus()
CommandButton1.BackColor = &H8000000F
<FONT color=red>End Sub</FONT>
</PRE>