You can translate numbers from decimal to hex easily enough with a lookup table!

n="62345"

essentially you find the largest value in your table less than n

example F000 = 61440

subtract that number from n, and look up the remainder

62345 -61440 = 905

example 0300 = 769


Using string manipulation, you figure out that n is F3xx


the table doesn't need 64000 entries, 64 is about enough for 4 char hex