lxUseCell property: how to detect it ?

Hi,

I would like to write a skill which will warn me if property
"lxUseCell" is present somewhere in my schematic.

In my CIW, I tried

SchemContents = geGetWindowCellView()~>instances
x = nthelem(1 SchemContents)
x~>master~>??
x~>??

and then i read the results ... but nothing appears about "lxUseCell"

so, how to detect this property ?

Thanks for your help,

b.