[AccessD] need help with date-query

Dear List,

For the Cataract performance indicators, i have to find out how many patients with a cataract operation at both eyes, have done a post-checkup after the first operation, but not before 14 days.

So i have a table with three fields.

Patientnr          Code            Date
01111111         031241            01-04-10
01111111         190013            20-04-10			
01111111         031241            25-04-10
01111111         190011            26-04-10
02222222         031241            01-05-10        
02222222         190011            05-05-10
02222222         190012            07-05-10
02222222         031241            01-06-10
02222222         190013            04-06-10
04444444         031241            01-07-10
04444444         190013            20-07-10
04444444         190013            22-07-10


The code for cataract operation is: 031241
The codes for post-checkups are: 190011, 190012, 190013


as result i would like:
Patientnr          Days
01111111           19


Patientnr 02222222 does not match the criteria, because the post-checkup is 4 days after the first operation.

Patientnr 04444444 does not match the criteria, although the post-checkup is 19 days after the operation, there isn't a second operation.


I'll hope someone can help me with this.
Although i can level the patients down to those who have two operations and checkups, but when there are more then one checkup, i have to control them by hand.
This is a lot of work.

Thanks

Pedro