This collection of weird shapes is the fill font for Punched Out, so you can easily make your own custom made design on the letters. This can look pretty cool I'm sure...

The lowercase are if you really just wanna fill the front of your letter, the uppercase are for all visible surfaces.

For the frontside-only numbers:
US/UK keyboard: just use shift + number.
Swiss keyboard (ok, this is selfish, haha): just use alt + numbers
for any other keyboards:
1 = ! or ±
2 = @ or "
3 = # or £
4 = $ or Ç
5 = % or [
6 = ^ or ]
7 = & or |
8 = * or {
9 = ( or }
0 = ) or ≠