So i've got the writing thing going, but can't seem to get reading an xlsx file to work

I've tried a combination of setXlsxFilename, openExistingExcelFile, openExistingWorksheet and set CurrentRow.

getCellContent keeps throwing Cannot get content - Column/row not found. Guessing my source file isn't being read or setup correctly

Can someone paste a code snippet of the sequence of opening up a file?