[Ifeffit] Making N (coordination number) a variable.

Hello Is there a way in artemis to make N, coordination number, a variable to be used in GDS window? I do realize that N and ss are closely linked and do very similar things in the fit, but it seems i may need fractional (average) coordination number for one of the paths, and am fine fixing ss to see where N levels off. Thank you very much. Alex Solov