using aggr with an if statement

[#1]

Hi,

I'm trying to create a subtotal uisng an if statement

Sample Data

Products	Rejected	Count
Total		6,458
Product 1	0	2,000
Product 2	1	2,592
Product 3	2	1,866
Solution required			%
Product 1	0	2,000	31%
Products 1 to 2		4,458	69%
For Selected Dimensions		6,458	100%

So, I need to add Products 1 to 2 toghether and express it as a % of the totlal of each dimension a user selects.

Thanks in advance.

Brian