Help with xmodmap and alt key

i have an aa1 with a english/french keyboard. i order to make it more comfortable for myself, i've remapped a few keys

the useless key next to the left shift is now part of the left shift as was posted on another thread on here
i disabled my capslock and made it another shift key as well
i also made the other backslash key next to my enter key part of the enter key too
only one i cant figure out is how to make the alt car key function like the alt key. if anyone has any tips on this i'm all ears!

Code:

keycode 94 = Shift_L
keycode 66 = Shift_L
add shift = Shift_L
keycode 51 = Return
clear Lock

i dont know if thats the best way of doing it or not but its my first day using linux and thats what i came up with searching on here and google and experimenting. if anyone has some insight on what to do about the alt car key, i'd appreciate it.