Average values in Excel that fulfil a condition referring to many columns

I’m actually used to Excel but not able to solve the following problem:

My column AA consists of 300 records with values of which I wanna calculate the average but I dont want to calcualte the average of each value, I rather want to average all values that fulfil certain conditions. The result should be shown in one cell, I DON’T WANNA USE A HELP COLUMN.

I’ve already tried AVERAGEIFS :

AVERAGEIFS($AA:$AA,$BW:$BW,<>0,….

but I’m not able to implement my complication condition:

(ROUND($AG:$AG+($AG:$AG*(1-IFERROR(AI:AI/$AG:$AG,0))),0)) = (ROUND($AH:$AH+($AH:$AH*(1-IFERROR(BC:BC/$AH:$AH,0))),0))

So I only wanna average the values of column AA that meet the condition BW<>0 and the complicated condition above in the same row.

Is anybody able to help?

Thank you!