I want to create a spreadsheet that will automatically calculate a sum... I
have no idea how to do this...

My Telephone section took 1563 calls.

All these calls added together took 80:39:43 (HH:MM:SS)

Is there any way I can get staff to enter these numbers in to Excel to work
out the AVERAGE call length in MINUTES?

Any help is much appriciated, though I am virtually clueless when it comes
to Excel.

Thank you,

--
Rob,
Teesside,
UK