Hi Hanan,
I don't know how, or even if, those files can be edited. You need to find the TTF file for a font type that includes the characters you need. Perhaps something from here: https://arabicfonts.net/.
Thatsite allows you to type in test text, so you can ensure that the problematic characters are included in the font.
Then follow the instructions above to create the three files needed for Moodle from that TTF file and add them to your Moodle site.
Hope that helps,
Aaron