Problem with nested functions.

I have a simple spreadsheet which uses the AVERAGE function to find the sum of the 10 largest numbers in a named range of 50+ numbers. This works fine as it stands. I wish to use this in an IF function to give me a value of 0 if there are less than 10 entries in the named range. My IF statement reads =IF (counter)LT 10,0,=AVERAGE…..

This fails every time.

I am sure that I can use nested functions in this way but am getting very frustrated.

Can anybody help me please?