Fixed structure of rows

Hi experts
I am newbie in BIRT
I have to create fixed structure of rows with filters. For example:

Checknumber Amount
=AG240323
=AU364101
=AH612904 + AK412714
=first row + second row
etc.

What is the best way to set different filters by Checknumber on each row, and put formulas in certain row
What kind of report item should I use and how to restrict it?

Thank you in advance