Simplifying Profit Calculation?

Greetings Aronium Development Team

I am trying to have a report which does the following calculation:

 ( Sales Value over a specified period of time - ( Purchases included in a specified period of time + Specified Period of time expenses  + Products sold in the specified period of time cost ) ) = Total Profit over specified period of time..

But, the system gives only sales profit and margin which does not include calculating some costs as I noticed from browsing in the report's list. For example, it does not include my rent that I registered as an item in the system or some other expenses..

Could there be a report which does the same calculation above?

It would really be a great time saving report, and would be very handy. 

Best regards,

Skelty