Excel: Complex Unique Count - Is This Possible?

Hi All, I'm ideally looking for a one-cell solution, happy with a formula or VBA function (it needs to be able to update as the background data updates though). I have a data set in the background similar to the below (assume "Name" is in Cell A1):

 Name Account Item Group Sales Person A Account 1 Item 1 Group 1 \$1,500 Person A Account 2 Item 1 Group 1 \$500 Person A Account 1 Item 2 Group 2 \$500 Person A Account 2 Item 2 Group 2 \$500 Person A Account 3 Item 1 Group 1 \$2,500 Person A Account 1 Item 3 Group 1 \$1,500 Person A Account 2 Item 3 Group 1 \$2,500 Person B Account 4 Item 1 Group 1 \$500 Person B Account 5 Item 1 Group 1 \$700 Person B Account 4 Item 2 Group 2 \$500 Person B Account 5 Item 2 Group 2 \$500 Person B Account 4 Item 3 Group 1 \$500 Person B Account 4 Item 4 Group 2 \$2,500 Person B Account 5 Item 1 Group 1 \$1,500
(The above would be updated on a monthly basis; it would remain in the same format, but the values and the number of rows would change.) There is then a separate worksheet, which contains a data validation drop-down, allowing a user to select a "Name". I need to be able to calculate the unique number of Accounts, linked to that selected Name, which have total sales for Group 1 >\$2,000. Using the above example, if a user had selected Person A, the result would be: 3 (the 2 x orange font lines for Account 1, the 2 x blue font lines above for Account 2 and the 1 x red font line above for Account 3). Is there a way to perform the aggregation of sales at Name/Account/Group level, then calculate the number of those aggregations which meet a set criterion (in this case >\$2,000)...? Any help greatly appreciated. AP