Christian,

You lucky dog <g. Yes, it can be done the way you ask. The following
formula will do this, based on the indirect function. As you see,
essentially we are replacing the expression A1:A10 with the expression:

INDIRECT("A1:A"&COUNT(A:A))

This assumes that your data start from 1 and subsequently you have all
numbers. If for example your data start from A2, it should be:

INDIRECT("A2:A"&COUNT(A:A)+1)

An alternative is to write the range, say, A2:A3562 in a cell E1 (enter
it as simple text) and use instead

INDIRECT(E1)

The full formula for cells starting at A1 is:

=AVERAGE(IF((PERCENTRANK(INDIRECT("A1:A"&COUNT(A:A )),INDIRECT("A1:A"&COUNT(A:A)))0.6)*(PERCENTRANK( INDIRECT("A1:A"&COUNT(A:A)),INDIRECT("A1:A"&COUNT( A:A)))<0.95),INDIRECT("A1:A"&COUNT(A:A))))

Again to be array entered.

Regards,
Kostis