using System.Text.RegularExpressions;
public static void Main()
Console.WriteLine(Regex.Match("1000 - 1009 ABC1 ABC SOMETHING ELSE", @"^(\d+)([\s\-]+)(\d+)"));
Console.WriteLine(Regex.Match("1500-2000 ABC1 ABC SOMETHING ELSE", @"^(\d+)([\s\-]+)(\d+)"));
Console.WriteLine(Regex.Match("3295 - 2000 ABC1 ABC SOMETHING ELSE", @"^(\d+)([\s\-]+)(\d+)"));