Roy,

Create 2 report variables:

rnDetLine: 0, 0, Count, Reset at the end of the group
rnSumZ: IIF(rnDetLine=1, z,0), 0,  Sum, Reset at the end of the Report

In the Summary band put field with expression rnSumZ.

>I have a report with a grouping and the details,
>
>basically data is like this

>x   y     z
>200 test  80.00
>200 test2 80.00
>200 test3 80.00
>300 abc   20.00
>300 abc2  20.00
>300 abc4  20.00
>400 zzz   50.00
>400 zzz   50.00

>
>basically I'm grouping by x showing y for the detail and z for the total for each grouping but not as a sum, it's the total repeated in each item of the grouping, so the grouping totals would be:
>
>200 = 80.00
>300 = 20.00
>400 = 50.00
>
>Grand Total = 150.00
>
>How can I accomplish this?