Hello,

If I understand this correctly, we need to search for the C10 value in
A1, C1, E1, G1, ... and then we would like to get the next value right
to the found one returned.

I suggest to introduce a helper row:

Select row 2 and array-enter:
=INDEX(1:1,1,COLUMN(1:1)*2-1)

Now enter normally into C1:
=INDEX(1:1,MATCH(C10,2:2,0)*2)

Regards,
Bernd