XIRR query for cashflows

[xlForum2013]

I have a query with regard to XIRR calculations. I hope this is the right place to post this.
If you look at the attachment, there are three sets of cashflows. If you sum columns D and E you would get the same cashflows as in column C.
The question is how do you derive the XIRR value in column C using those from D and E.
05-Nov-13 12-46-04 AM.jpg

Thanks in advance.

[STill_matic]

I think you would just calculate with the same XIRR you used for C and E. Even though D and E sum to C, there IRR's are unique. For example, the ROI on C,D,E are 5%,20% and 2.35%, therefore you can't assume to have the same IRR. Also remember IRR is time weighted.