Multiply Dimension in a Note

My company posts the blank size of sheetmetal parts on their drawings as a note. This typically looks like:

PUNCH -- 7.743 X 33.613 -- MAKES 1 PC.

I have changed the method to associate the note dimensions to with actual dimensions. This allows the note to become "smart" and update correctly with most changes to the overall size of the blank. The note, as seen in the text editor is:

{0:PUNCH -- }{1:&add34}{2: X }{3:&add33}{4: -- 1 PC.}

Occasionally, we use a multi-blank (where 2 or more parts are punched at the same time. In this case, the referenced blank size needs to be adjusted for the correct number of blanks. The note should then read something like:

PUNCH -- 23.229 X 33.613 -- MAKES 3 PC. (where 23.229 = 3 * 7.743)

I would like to try and find a way to put this multiplication of the dimension into the note. Currently, this is done by hand, so that if the 7.743 dimension changes to 8.000, we must manually edit the note and change it from 23.229 to

{0:PUNCH -- }{1:&add34 * 3}{2: X }{3:&add33}{4: -- 3 PC.}

If you know a way, or can suggest an alternative, it would be greatly appreciated. Thanks, Matt