Change date format inside rename formula

I have a list of files with series date format and I want to rename them using YY-MM-DD format
The formula I use to rename is ="REN """&F13&""""&" """&G13&""""
wich I then paste and run on a bat file.
The problem is even if I change the format on the G13 cell to 09-04-06 on the formula it always shows 39909 independent of the format i use on the formula

Anyways around this.

SOLVED

TY sweep