Are you trying to take a 1 dimensional array and use the 0 row variable? If so, just
$var = $rFileList[0]
I would assume _ArraytoString would work with 0 as start and 0 as end, but as you indicated giving it 0 , 0 returns the full string deliminated value of the array, not just row 0
If you aren't using a 1 dim array respond back, you can't use arraytostring with 2 dim arrays anyway, but I can give an example if your confused.
someone's post in ArrayToString only row 0 was marked as the answer