restricting path-line xy-plots to specific axes ranges
 

I have successfully run fluid flow simulations through various geometries of interest and am interested in ascertaining the pathlength of flow through the structures. I can use xy plot in the pathlines menu but would like to write data to a text file over only a specific range of the dependent variable (in my case y-coordinate). Although I can restrict the fluent generated window plots to the axes limits of my choice, whenever I try to "write to file" it writes ALL pathlength data for all y coordinates. Which are very LARGE files that are difficult to work with. I'm using FLUENT 6.3.26. Any assistance would be greatly appreciated.