using AHK
its HKN

..the above script should do the job.
So, as Anemo suggested i would also try to change the hotkey delay beginning from 100/100.
If this works try to find out the magical frontier of the setting by tuning it down till it doesn't work

Perhaps you could also use SendWinMF instead of SendWinM to see if it works.

Edit1:
Other idea: is scrolllok on on every computer you use, or do you need it at all?

Edit2:
More comments: If you mean by relative mouseclicks, that the mouseposition is scaled according to your window-size the above should work