I am having a huge issue with having to use simple functions with data coming
from several sheets. Is there such a thing as a "compound function"? For
instance "AVERAGE(C17)" C17=('Sheet1'!A1,'Sheet2'!A1,'Sheet3'!A1). My next
calculation would be STDEV(C17), instead of re-entering all of the other page
references.

Part A: AVERAGE(C17)
Part B: C17=('Sheet1'!A1,'Sheet2'!A1,'Sheet3'!A1)