>What is the proper way to define a textbox if the data field is C(12,2) and the display should include the comma separaters? I would think an inputmask of ###,###,###.## would do it but this displays the commas even when the data is empty. Can't we display the commas only when there is data?

I assume you meant N(12,2).

Add a Z into the .function property of the textbox ("blank when zero")