Hi Hamed,

Firstly, why do you want to average PEEQ.  Remember that PEEQ dosn't converge easily. You need elements size equal to the thickness to get  reasonable PEEQ. 

Secondly,I  think you can get the history output for PEEQ. Get its data file and export it into Excel and do whatever your heart desires. 

I haven't doing work last four years and I ma more than a little bit rusty.