This is not my original work and the author is unknown, but I have modified it for my use case and to compile with tbaMUD v2018. The function converts an input value (currently a long int) to a string with commas. Useful especially for exp and gold values as they increase in the endgame.
Converting it to an 4bit int input is trivial so I leave that to you.
You will have to change your output to characters to a string instead of an int to avoid breaking your game.
Code:
Level 1 requires: 10,000 experience, 10,000 total experience
Level 2 requires: 20,000 experience, 30,000 total experience
Level 3 requires: 30,000 experience, 60,000 total experience
Level 4 requires: 40,000 experience, 100,000 total experience
Level 5 requires: 50,000 experience, 150,000 total experience
Level 6 requires: 60,000 experience, 210,000 total experience
Level 7 requires: 70,000 experience, 280,000 total experience
Level 8 requires: 80,000 experience, 360,000 total experience
Level 9 requires: 90,000 experience, 450,000 total experience
Level 10 requires: 200,000 experience, 650,000 total experience
Level 11 requires: 220,000 experience, 870,000 total experience
Level 12 requires: 240,000 experience, 1,110,000 total experience
Level 13 requires: 260,000 experience, 1,370,000 total experience
Level 14 requires: 280,000 experience, 1,650,000 total experience
Level 15 requires: 300,000 experience, 1,950,000 total experience
Level 16 requires: 320,000 experience, 2,270,000 total experience
Level 17 requires: 340,000 experience, 2,610,000 total experience
Level 18 requires: 360,000 experience, 2,970,000 total experience
Level 19 requires: 380,000 experience, 3,350,000 total experience
Level 20 requires: 600,000 experience, 3,950,000 total experience
Level 21 requires: 630,000 experience, 4,580,000 total experience