Foudah,
All you need to do is add the function "Write to Spreadsheet file" from the "File I/O" subpallet. There are two ways to do this. In the first example, a row of readings from multiple strain gauge measurements is appended to a text file every time the loop executes. The first time through the loop, a dialog box will appear asking for the file name as nothing is wired to the "filepath" terminal (you could wire a control), a shift register handles each subsequent execution of the loop.
In the second example the readings are gathered into a 2D array at the loop boundary and all sent to a file at once.
Hope this helps.