Set the state of a cell to edit??

[GSMike]

Is there a way to do that?
I am trying to help the user enter a function that is in their Personal workbook. When we use the Insert>Function>User Defined Fuctions...method, we get weird stuff going on, since there's an InputBox in the function. You have to answer the input box like 6 times when you use that interface.
So what I would like to do is create a shortcut key that enters "=Personal.xls!MyFunction(" in the cell and leaves the cell in edit mode, so the user can then type in or select the cell that is used as a parameter for the function.
I've been trying:

ActiveCell = "'=Personal.XLS!quincy("
ActiveCell = Right(ActiveCell.Value, Len(ActiveCell.Value) - 1)

, etcetc
But obviously none of this works.
Here's the function in question, in case that will help you see what I'm trying to do.

Function Quincy(x As Range)
If ActiveWindow.RangeSelection.Cells.Count = 1 Then
    Prefix = InputBox("Please enter the prefix you want added to the selected cell value.", "The Quincy Prefix Function", "66")
End If
Quincy = Prefix & CStr(x)
End Function

Thank you for your help!
Mike