How do I format a number in the "Lines and Tax" section of a BPA template

I don't know if this should be asked here or maybe under BI Publisher.  I did not notice a place for BPA, but maybe I missed it.  I am creating a custom template for a type of invoice.  I have created a custom "Lines and Tax" view.  In the view, I call a function to find the amount that is still due on the invoice after payments and credits.  That function returns a number, and then I would like to format it to display "nicely" in the report.  However, whenever I format it, the number comes out "garbled".  It is