Currency Modelling

Hi Experts,

I got struck at some logical point. I am currently modeling for currency field. I have one field which give me amount gained or lost. I am extracting this field from external source system (Not R/3 , from flat file). This gives me indication about amount gained or lost like following way i.e. +500 for Gained and -500 for the lost.

Now, the problem is arise at the designing info object. What should be data type assign to info object so that I can use that info object any calculation, aggregation etc. and at same time it should indicates that amount is gained or lost.

Regards,

Aniruddha