First, let me point out that you are not using Excel. You are creating a text file with tab separated data and giving it an .xls extension. Excel will automatically open aand convert this file for you. You could put a table on the front panel and display the results there. A table is a 2D string array and you could convert the 2D numerical array to that with just a Number to Fractional String function. You could also actually use Excel native format. There is a shipping example called Write Table to Excel. This opens Excel and writes to it.