mouse emulation with keyboard in X

[Juraj Fedel <wwm@inmail.sk>]

I offten use mouse emulation (activated by Ctrl+Alt+NumLock). It
works fine, my problem is that emulation is automaticaly
deactivated if not used for a while. How do I prevent this.
In man Xserver I found command line option:
   [+-]accessx [ timeout [ timeout_mask [ feedback [ options_mask ] ] ] ]
            enables(+) or disables(-) AccessX key sequences.
The question is where do I put this option and what values do I
use (my guess is +accessx 0). What does all that optional values
stand for - I did not find any more info about this option that that
two lines!
Juraj