If you can browse to your text file using Windows Explorer then the easiest is to just enable the browse function of a file path control on the front panel of your vi, browse to the file, and then run the vi. You can then save right click on the control that now contains the desired path, go down to "data operations", "make current value default", go to the diagram side of the control, right click on the control and "Change to Constant", giving you a file constant with the path to your file, if you want a fixed path.
PutnamCertified LabVIEW Developer
Senior Test Engineer North Shore Technology, Inc.
Currently using LV 2012-LabVIEW 2018, RT8.5

LabVIEW Champion