Range.CountLarge (Excel)
Returns a value that represents the number of objects in the collection.
The CountLarge property is functionally the same as the Count property, except that the Count property will generate an overflow error if the specified range has more than 2,147,483,647 cells (one less than 2,048 columns). The CountLarge property, however, can handle ranges up to the maximum size for a worksheet, which is 17,179,869,184 cells.
Dim lngCountLarge As Long
lngCountLarge = ActiveCell.CountLarge