Moving a Sum Range Based off of the Month

[dash11]

I've come across a situation where I have a report that is setup to sum rows across columns that represent the months of the year. I want to have a sum formula at the end but only want it to include the completed months with data. Meaning, the data source driving the report will be pulled from a point in time that may have some data for November 2014, even though we're still in October. Instead of going to the data source and manually excluding those, or adjust the sum range to not go as far as November, I'd like to have some sort of "OFFSET" type lookup that would adjust accordingly. I've attached an example.

[Pepe Le Mokko]

Like This?

[dash11]

Exactly!!! Thank you!!