In the sheet formats I've set up, I use a note to show the filename of the model being used in the drawing. Currently I'm using $PRPSHEET:{SW-File Name} to do this, with the extension (.SLDPRT) manually entered behind it. The problem is that when I make a drawing of an assembly, I have to remember to change the extension on the drawing.

Is there a way to get the model's file name with the extension included automatically?