Using cell references to construct data ranges in chart data selection

I have a workbook with one large data sheet and several graphs. The data is updated frequently by adding rows and this requires manually changing the selected data in each chart data selection window. For example, the Chart Data is specified as
=Data!$C$1:$C$56,Data!$M$1:$O$56.
I want to have cells in the Data sheet that let me specify the values for the rows (1 and 56 in the example) to be displayed on the charts. This would allow faster updates but also allow "zooming" on sections of data.
When I try using any formulas in the Select Data window, I get a variety of messages that don't make sense, leading me to believe it simply cannot be done. Any thoughts?

Hi
I supose you can use INDIRECT
=INDIRECT("Data!$C$1:$C$"&X1),INDIRECT("Data!$M$1:$O$"&X1)
where X1=56

Thanks. I tried something similar before posting. Your suggestion made me realize I had made a syntax error, but when I try your suggestion as you gave it, if tet a window telling me "the function is not valid". I seem not to be able to use any functions in the data select window