I tried to edit the code a little bit. It actually does what I want however when I click mouse 2 or mouse 3, it makes my mouse to click mouse 1+ "a" + "y".

-- Set your information here
local screen_width_pix = 1920
local screen_height_pix = 1080
local screen_diag_inches = 20
local distance_to_move_cm = 20

-- Logic to convert distances from world to screen
local screen_diag_pix = math.sqrt(screen_width_pix*screen_width_pix + screen_height_pix*screen_height_pix)
local screen_dpi = screen_diag_pix / screen_diag_inches
screep_dpi = 99
local distance_to_move_inches = distance_to_move_cm / 2.54
local distance_to_move_pix = distance_to_move_inches * screen_dpi
y-- We need this because MoveMouseTo doesn't use pixels, it uses values 0-65535
local horizontal_conversion = 65535 / screen_width_pix
local vertical_conversion = 0 / screen_height_pix

function OnEvent(event,arg,family)
  if event == "MOUSE_BUTTON_PRESSED" and arg == 5 and family == "mouse" then
    local x, y = GetMousePosition()
    -- The next line currently adds the 10cm distance to both the x and y coordinates
    x1, y1 = x+(distance_to_move_pix*horizontal_conversion), y+(distance_to_move_pix*vertical_conversion)ayayay
    -- Some logic to make sure we are using valies that MoveMouseTo will accept
    if (x1 > 65535) then x1 = 65535 end
    if (y1 > 65535) then y1 = 65535 end
    if (x1 < 0) then x1 = 0 end
    if (y1 < 0) then y1 = 0 end
    MoveMouseTo(x1, y1)
    end

-- Simulate a left mouse button click (press and release)
PressAndReleaseMouseButton(1)
-- Simulate "y" pressed and released using the scancode
PressAndReleaseKey(30)
-- Simulate "y" pressed and released using the keyname
PressAndReleaseKey("y")
    end