I have a workbook with one form, at the bottom of the form
is a text box (txtStatus) which I would like to display a
status message. I show the form and the user selects some
options and clicks a button to process. In the click event
of the button, I set the txtStatus.value
= "Processing...". But, it doesn't immediately update the
form, the next time I show the form it is there. I need
to have the form that is currently being displayed have
this text box updated immediately, is this possible?

The command - DoEvents - may be what your looking for it updates userforms such as progress bars from within macros.

Just place the DoEvents statement after your statement setting the txt box's value

hope this helps