I have regular expression (?!\,)(?!X){3}[0-9\.\w\s\+\-\:\,]+ and strings like
"1", "S1", "S2", "1", "2"
"1", "S1", "S2", "1", 2
"1", "S1", "S2", "1", "2", 3
I am trying to parse that string with Regex (by matches) and I am not strong in regular expressions.
I need to process elements "1", "S1", "S2" and to skip elements "1", "2". The first idea is to specify in regular expression logic like "don't take occururences, that are first from right ("2"-2) and second from right ("1"-1), but take all other occurences".
The main idea is that this logic should be made with only regular expression, not by C# code (I am talking about Match object position in C# matches array - no C# logic, regular expression should be used only).
How can I change my regular expression (?!\,)(?!X){3}[0-9\.\w\s\+\-\:\,]+ to specify positions, that are should not be processed?