Keyboard remapping

ok, so we all know there's unicodes, and normal letters/numbers.

how would i go about changing the keyboard map to a specific unicode ?

EX...
if i was to type this
"that's fancy."
it would turn out like this
"that's ƒancy."

and so on, so fourth with all the keys i could want/would change.... this would also be a very good "cussword bypass" for video games, cuz they don't realize ALT+159 = ƒ = F

i think this will help you The Microsoft Keyboard Layout Creator