How to remove unused glyphs from the font file?

[orhanyor]

Hello, Im trying to create a smooth font file with only numbers in it to reduce the file size. Currently tried to remove the unused glyphs with FontForge but in the end it still somehow adds generic letters to the end result but maintains whatever I did not delete. So numbers stay the same but all the deleted letters are getting replaced by some generic font.
Is there any other way to delete the letters lets say after converting them to the C array? Thank you

[orhanyor]

It is all sorted out, turns out create_font.pde has all the necessary modifications i need to include whatever glyph i want.