Control for entering formulas

[dosgators]

I want to add a control to a form that allows the user to enter formulas, including cell references via clicking (like in RefEdit). I need to do this on a form, so can't use an InputBox, which I know can take formulas. If I use the RefEdit control, it only accepts a range and not a full formula - it seems to overwrite any text the user has entered whenever a range is clicked on with the mouse. Any suggestions on how to do this ? Thanks.