[PRISM II] ajusting "cnfsystemscale" parameter ?

Hi,

I've to configure some Fujitsu Tablet PC equiped with Intersil Prism
II chipset in a hight density access point network (15 access point
"Dlink DWL-900AP+" in one little building). In fact we have a lot of
access point to get a perfect coverage (private clinic).

We have a little problem : the wireless card rescan threshold is to
low (probably 0dB to rescan for a good AP). We want to place a highter
threshold for the rescan to always get good performance.

I can see on the intersil website that the "cnfsystemscale" parameter
do this job with 3 differents threshold ajusted with the AP density.

Is somebody can explain me how i can ajust this parameter with a
Windows XP Tablet (or Pro) system : perharps a registry key
modification...

I use the intersil utility to configure my connection.

Thanks in adance for your help and excuse me for my very bad english
;-)

Xavier
(E-Mail Removed)