Format Date without using Format Feature

We have a script that runs to pull up a date and enter that on our form. We cannot update the script from our system to get the date to be entered in the format that we would like. It's being entere as yyyy-mm-dd. We would actually like it to be entered as mm-dd-yyyy.

I tried to change the format for the field to the Date format, but then the date does not get placed on the form at all. Is there a way to change the date format without using the format feature? Maybe I need to have the date entered in the "Last Date Positive" field, but have that hidden. Then create another "Date" field that will manipulate the date field to be in the correct format?