using System;
using System.Text.RegularExpressions;
public class Example
{
public static void Main()
{
string pattern = @"\bN[^\W_]{3,6}\b";
string input = @"N and will have combination of 3 to 6 letters or numbers with it ie. N24 or NX747 or N35655V but it should ignore N2 or N8(N plus 1 character) or N1234567(N plus more than 6 characters";
foreach (Match m in Regex.Matches(input, pattern))
{
Console.WriteLine("'{0}' found at index {1}.", m.Value, m.Index);
}
}
}
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for C#, please visit: https://msdn.microsoft.com/en-us/library/system.text.regularexpressions.regex(v=vs.110).aspx