Compare expired dates to a required date and sum available inventory

I have a worksheet that lists multiple types and numbers of parts and their expiration dates. I need to compare these expiration dates to a date on another worksheet. For the parts that are greater than the required date, I need to sum these to create an inventory number. I was summing a nested if function, but there is a limit of 7. I am interested in any and every idea and your suggestions are greatly appreciated!

It would help if you could post a sample workbook which shows the data that you have and how you would like it to be processed.

Pete