Billable Expenses Unwanted grouping

I am putting together an invoice, half of which has employee billable miles and half company vehicle miles.  I'm can't get a date column on this invoice so I have entered the date for company miles into the description.  When I add the Employee Billable miles to the invoice, it groups the entries with like-memos together.  I assumed that the memo area in the expense report was the area to enter the decription as there was no other column for this.  I would like date to appear on this invoice so the client can see the dates for mileage broken