WKO+ doesn't have a canned AWC estimator that I know of. You could take a couple of points off your mean maximal curve and plug them into a Monod CP spreadsheet like the one you can download from this page: http://www.velo-fit.com/articles/critical-power.pdf
Ideally the peak efforts you plug into the spreadsheet should have been captured fairly close to each other instead of say a max 20 minute in August and a max 3 minute in January but it's still a good starting point. The efforts should also really be best efforts for the durations. If you want a better estimate you should plan a CP testing session (or two if you need more recovery between the short and long efforts) following some rest days.