Autonumbering a column

Hi,

I am wanting to have an autonumber from A5 downward, but only when someone enters a new row.

I want the number to be something like INC0001, then INC0002 etc.

Can anyone help?

Naomi

Can you just format those cells with a custom format like this?

"INC"000#

I would, but they want it automatically - so that they don't really have to do anything themselves.

Would they be inserting a row at the bottom of the data? I'm just confused. A Custom format, all they user does is enter the number, and INC00 is included automatically?

When the user inserts/adds a new row? I would think this should be numerical correct?