Here is just a quick snippet of code that took me a while to do so I thought it might help someone else.

I needed some code that did rebindable controls like you see in many AAA games.

This code is just an array of the standard buttons on a QWERTY keyboard with the array key being its ASCII code and the array value being a human readable name for that button. In GameMaker when dealing with keyboard commands it gives each key a number, the number is the same as its ASCII value.

key[9] = 'Tab'
key[8] = 'Backspace'
key[160] = 'Left Shift'
key[162] = 'Left Control'
key[164] = 'Left Alt'
key[165] = 'Right Alt'
key[92] = 'Right Windows Key'
key[163] = 'Right Control'
key[161] = 'Right Shift'

key[12] = 'Num 5' // This is actual Num 5 but when Numlock is off, even Wiki says it "Does Nothing"
key[13] = 'Enter'

key[16] = 'Shift'
key[17] = 'Control'
key[18] = 'Alt'
key[19] = 'Pause'
key[20] = 'Capslock'

key[32] = 'Space'
key[33] = 'Page up'
key[34] = 'Page down'
key[35] = 'End'
key[36] = 'Home'

// key[27] = 'Escape' // cant be used because its used to exit this menu

key[37] = 'Left'
key[38] = 'Up'
key[39] = 'Right'
key[40] = 'Down'

key[45] = 'Insert'
key[46] = 'Delete'

key[48] = '0'
key[49] = '1'
key[50] = '2'
key[51] = '3'
key[52] = '4'
key[53] = '5'
key[54] = '6'
key[55] = '7'
key[56] = '8'
key[57] = '9'

key[65] = 'A'
key[66] = 'B'
key[67] = 'C'
key[68] = 'D'
key[69] = 'E'
key[70] = 'F'
key[71] = 'G'
key[72] = 'H'
key[73] = 'I'
key[74] = 'J'
key[75] = 'K'
key[76] = 'L'
key[77] = 'M'
key[78] = 'N'
key[79] = 'O'
key[80] = 'P'
key[81] = 'Q'
key[82] = 'R'
key[83] = 'S'
key[84] = 'T'
key[85] = 'U'
key[86] = 'V'
key[87] = 'W'
key[88] = 'X'
key[89] = 'Y'
key[90] = 'Z'
key[91] = 'Windows Key'

key[93] = 'Context Menu'

key[96] = 'Num 0'
key[97] = 'Num 1'
key[98] = 'Num 2'
key[99] = 'Num 3'
key[100] = 'Num 4'
key[101] = 'Num 5'
key[102] = 'Num 6'
key[103] = 'Num 7'
key[104] = 'Num 8'
key[105] = 'Num 9'

key[106] = 'Num *'
key[107] = 'Num +'
key[109] = 'Num -'
key[110] = 'Num .'
key[111] = 'Num /'


key[112] = 'F1'
key[113] = 'F2'
key[114] = 'F3'
key[115] = 'F4' // was left black
key[116] = 'F5' // was left black
key[117] = 'F6' // was left black
key[118] = 'F7'
key[119] = 'F8'
key[120] = 'F9' // was left black
key[121] = 'F10'
key[122] = 'F11'
key[123] = 'F12' // was left black

key[144] = 'NUMLOCK'

key[173] = 'Mute'
key[173] = 'Volume Down'
key[173] = 'Volume Up'

key[186] = ';'
key[187] = '='
key[188] = ','
key[189] = '-'
key[190] = '.'
key[191] = '/'
key[192] = "'" // actually `

key[219] = '['
key[220] = '\'
key[221] = ']'
key[222] = "\#" // actually # but that needs to be escaped

key[223] = "`" // actually ` but that needs to be escaped
    

And in case you wondered this is how I did the rebindable part:

changeinput = 0 // if this = 1 the player wants to select a new button for this command 
valuep1 = vk_space // this should be loaded from a save file is the keypress code

STEP EVENT:
if (clicked()) {
	changeinput = 1 // checking to see if the player wants to change this key
}
if (keyboard_check_pressed(vk_anykey)) {
    if (keyboard_check_pressed(vk_escape)) {
        changeinput = 0
    } else {
        if (changeinput == 1) {
            valuep1 = keyboard_key // This where the player selects the new key they want to rebind
            changeinput = 0
        }
    }
}
if (changeinput < 0) {
    changeinput = 0
}


DRAW EVENT:

if (changeinput  == 0) {
    draw_set_colour(c_gray)
    draw_text(x,y,key[valuep1])
} else {
    draw_set_colour(c_black)
    draw_text(x,y,'Press Key')
}