Return Column Header from Index/Match function

Have looked everywhere to try and solve this, not sure if it can be done, anyhow here goes.

I want to lookup the value in cell c2 in the 1st column of an array (F1:U23) and return it's row reference in that array (that's no problem). I then want to match the value in cell b2 in that row and return the coumn header from (F1:U1).

I want to achieve this for a list a values from c2:c8762 and b2:b8762.

Is it possible maybe to use a cell reference for a row range/ lookup array?

The spreadsheet is attached.

All input greatly appreciated.

Try:

=IFERROR(INDEX($M$1:$AA$1,MATCH(B2,INDEX($M$2:$AA$23,MATCH(C2,$L$2:$L$23,1),0),-1)),"")

copied down.

Blank returned if number in column B is bigger than largest value in respective row for column A value.