Counting number of unique numbers based on another variable.

Hi All,

I have a problem that I've been trying to resolve but just cannot find my answer.

I run a report that dumps from data from an ERP system. I've attached a sample of this report in excel that has two sheets. A summary and the data.

I am able to report on the total number of Purchase order lines and total purchase orders using various formulas. I am also able to use formulas to report on the number of lines associated with each product in the I column.

However I cannot for the life of me work out how to calculate the number of unique Po# (B Column) numbers based on the Product (I Column) and it's driving me insane.

Would someone be able to assist me?

Regards