I have some strings like:
I want to get all positions in the string that have the letter N
and then followed by 
. It's always the same pattern to search, namely N
But my problem is that, if I use the index function (which I thought was the right way to go, won't it count for instance the first occurence of 
as 5 characters? And, consequently, the index function would give a false position for the second 'N' in the string?