Query count more than

Hi,

I'd like to make a query for the number of customers who sells more than x products. For example customers who sell more than 1000 products.

To do this, in advanced filter, select order lines entity, filter by account, but I do not know how to count the number of occurrences of the account. I do not know how to use sum, avg, count, group by on advanced filter querys in dynamics crm.

Thanks