"Rolling" XIRR in Excel cannot, example, function, investment, 304

islandgyrl

I have a series of cash flows and investment NAVs at each cash flow date. Does anyone know an easy way to create a "rolling" IRR at each date using the XIRR function in Excel?

For example:

Date CF NAV “Rolling” IRR
1/1/11 -100 100 0%
1/31/11 0 102 27.2%
2/15/11 -100 205 48.5%
2/28/11 -100 304 22.5%

I cannot figure out a way automate this function in Excel using XIRR.

Thanks.