Read CRM data using RFC while creating document.

Hi Experts,

I want to read CRM data while creation of document(Opportunity), i know some of the standard FM CRM_ORDER_READ, _OW, _OB which will fetch all the data form work area/buffer, this FM works fine if we call this FM in same session i'm getting all new data belongs to new document, in my case i want to retrieve(through RFC from different system) CRM data which is not committed in DB?