Hi I am trying to use an Average function but I am a bit confused with the syntaxis.

=AVERAGE(D2:D & 'C2')

Cell c2 has a numeric value, which I want to put next to D. Say range d2:d5 but instead of 5 I want to put a reference to cell c2 which returns the value of 5. So whenever c2 changes Average also changes. Thanks a lot in advance.