I want to sum cel c4 from muliple sheets.
I know that i could use:
SUM('01:02'!C4)

The trouble is i do not know how many sheets i am going to make
So i have a function FIRSTSCHEET
I also have a function called LASTSHEET

What i would like is something like

SUM(Firstscheet():Lastsheet()!C4)

Is this posible

Greetings Hans