convert array formula output to string

Hi all,

I'm trying to turn the output of an array formula to a string so that i can use it inside an INDIRECT formula. My array formula is the following:

Please Login or Register  to view this content.

Column Q has letters in it (C through N) and R is 1 or 0 for each letter. In the end, I want the string to look something like this:

"C2,D2,E2,F2..." (assuming the formula was entered in cell O2)

Using this string, I would then be able to write an AVERAGE around it:

Please Login or Register  to view this content.

Thanks,
Joe

I'm not sure that would be the best way to approach this. Perhaps try this "array formula"

=AVERAGE(IF(TRANSPOSE(R3:R14),C2:N2))

confirmed with CTRL+SHIFT+ENTER

Note that doesn't reference Q3:Q14 so I presume those letters always remain the same......