I have a cell in which its value is determined by 3 other cells in order to
form a Date type of entire.

Example:
Cells O17, O18, and O19 are determined by combo box selections.

O17 = Month
O18 = Day
O19 = Year

Let's say that cell O20 uses the following formula:
=O17 & " " & O18 & "," & " " & O19

Cell O20 would be displayed as:
April 1, 2005

Is there a way I can force cell O20 to be seen as a date? I've adjusted the
cell formatting to 'Date' and I used the type as 'March 14, 1998'. However,
cell O20 is not in a Date format.

If I click in the formula bar for cell O20 and press enter, it then switches
to the Date format.
I need for this to be done automatically without me having to click in each
cell. I'm already using a macro to copy this cell from a different
worksheet. Can I add something to the macro to force this into a date
fomat?

Thanks,
Paul