Sql multiple Table columns Row wise Subtract in rldc Report

I Have Two Table, Table 1 Actual Expenditure for  and Table 2 For Proposed Budget. Now Table 1 And Table 2 have 4 columns

1. Expenditure Head

2. Expenditure Subhead

3. Expenditure Particular

4. Amount

which is sorted in groups 1. Expenditure Head < 2. Expenditure Subhead < 3. Expenditure Particular - 4. Amount.

 

I wanna Subtract the Group Wise Total And The Grand Total in .rldc Report and show it in report viewer..

PLease Help Out ...

 

And Thank You