Query with Difference in Total Sales

[Minkowski]

Hello everyone!
i have a DB with Total Sales for Product Alpha
the master table shows the sales i made fro today untill 2 years ago
what i want to do is this:
since i can see the sales for today and yesterday
i want the new sales=sales today-sales yesterday

i can do it with 2 queries
1)master table filtered to show sales today
2)master table filtered to show sales yesterday

then i create the difference:

Sales Made: [Today Sales Made].[Ttl Sales]-[Yesterday Sales Made].[Ttl Sales]

can i do this in one step without these 2 queries?
something like:

 [Today Sales Made].[Ttl Sales.Date()]-[Yesterday Sales Made].[Ttl Sales.Date()-1]

thanks in advance!!

 

[Minkowski]

Total Sales (is a field of the master table)

Sales Today: Total Sales
Criteria->Date()

Sales Yesterday: Total Sales
Criteria->Date()-1

and third field:

New Sales: [Sales Today]-[Sales Yesterday]

i believe this works...but i know there is a simpler solution