How can I tell if the user has selected a menu option or a popup?

I have a macro that calculates hrs distributed over time. The user can
select a menu to start the calculation or the user can double click on a
cell in a column I named "Spread" and get a form that allows them to select
the kind of spread - Increasing, Decreasing, Level etc.

I need to know if the user has selected the menu or the popup.

I tried this in the code:

MyPik = Application.CommandBars.ActionControl.Caption

This will capture the particular menu option but causes an error if no menu
option has been excecuted.

If MyPik has a value then I will execute a section of code otherwise I will
assume the user form and execute another.

Any suggestions?

Glen