Hi Agus,
I hope I got want you want. Try the following:
(1) Setup your row definition by including each and every main account that you have.
(2) Make all those lines "non-printing lines".
(3) Please do not use the main account categories but rather those categories yourself by specifying total lines in your row definition e.g. by saying that bank & cash is made up of the rows 100:150 or whatever line you specified.
(4) Generate your report
=> you should only see the total lines. If you drill down the first level, MR will show you subtotals by main acount. If you drill down to the second Level, you will once again have the breakdown main account-financial dimension.
All the best,
Ludwig