Trouble with my sorting and grouping

I a using Access 2007. I have a report based on a query. In the
report I am using the inbuilt sorting & grouping feature to calculate
totals for each footer record (including percentages of the grand
total.)

This all works fine but the records are coming out in alpha order
(company names) - I want them to be sorted according to the count of
each record in descending order. Access will only let me select a
query field to do the sorting in the sorting and grouping box.

How do I achieve my objective?

Gordon.