First time poster. I'm trying to sum cells from an earlier dated worksheet in order to maintain year-to-date counts for comparison. The way my workbook is setup now, I have one year's worth of data on each worksheet and the data used are monthly reports. The monthly reports are pasted into my 'Template' worksheet. The data from these is then organized into a time series on separate worksheets, and the name for each of the worksheets is the year for which the data corresponds. When adding new data throughout the course of a year, I was wanting to pull in year-to-date totals from the previous year in order to compare similar time frames. This is what my formula currently looks like.

`=SUM(INDIRECT("'"&LEFT($A13,4)&"'!C17:OFFSET(C$16,MONTH(RIGHT(Template!C$3,10)))"))`

`LEFT($A13,4)` references the year I want pulled in for the current worksheet, and `MONTH(RIGHT(Template!C$3,10))` identifies the number of the month for the current report. So, for May 2015, `Left($A13, 4)` would return `"2014"` and `MONTH(RIGHT(Template!C$3,10))` would return a value of `5`. 

As (I hope) is evident, I'm attempting to begin my summation at the beginning of the annual series found on the previous year's worksheet, and then use `OFFSET` to pull in only the months that end with the current report month for this year to do a year-to-date change. This is returning `#REF!` in Excel when I attempt to do this. First impressions make is seem that `INDIRECT` is not recognizing `OFFSET` as a function, and is treating it as text. Is there any way around this?

I see something similar was posted earlier, but was unable to translate to my situation. Any help would be greatly appreciated.