[AccessD] Syntax for finding value of an item in a collection

I have a collection for control names (e.g., colControls) which contains certain controls (e.g. txtLastName) on a form (e.g. frmFormA).  For example,  colControls(1) =  "[Forms]![frmFormA]![txtLastName]".

Let's say that txtLastname currently contains the name "Smith.  What is the syntax for finding the VALUE of colControls(1) , i.e., "Smith"?

Thanks,
Barb