hello! i need to make this program that lets the user input like for example 99 then the program will output 'c'.

i don't know how to start. but i thought about getting the first 9 first, then subtract 30h, the multiply it by 10. afterwards, add the other 9, then subtract 26, because c -> 99 -> is 63h in hexadecimal. but... when i try the others i need to subtract different values to convert them to hexadecimal. am i using the wrong approach?

thank you very much for your replies. :D