>If I understand correctly, you want to print headers or footers every time an expression changes?
>
>Give the command "Report | Data Grouping", and type an expression which should be checked, whether it changes. For example, for a month, this might be: left(dtos(MyDate),6)).
>
>This will create two new report bands, for this group. You can put report fields into these bands, to print the desired information each time a month changes.
>
>>

>>January         1 2     5 6 7 8 9    1213141516    1920212223    2627282930
>>February  2 3 4 5 6     910111213    1617181920    2324252627
>>

I want to print /different/ headers every time the expression changes.

The monthname was easy and I've got code to produce the header, but it's too complex for the Report Writer's expression builder. How do I pre-produce the date string and get the RW to use the correct one at the correct time?

The footer problem solved itself.