using System;
using System.Text.RegularExpressions;

public class Test
{
	public static void Main()
	{
		string line = "HELLO MYNAME IS1 = {P 111.11, O -222.22, L 333.33, L -444.44, Y 555.55}";
		Regex re = new Regex(@"^HELLO MYNAME ([A-Za-z0-9]+) = {([A-Z]\s[+-]?[0-9]+.[0-9]+,?\s?)+}");
		MatchCollection matchCollection = re.Matches(line);
		foreach(Match m in matchCollection)
		{
		    Console.WriteLine("Match: ");
		    Console.WriteLine(m.Groups[1].Value);
		    foreach (Capture cap in m.Groups[2].Captures)
		        Console.WriteLine($"No {cap.Index} Value: {cap.Value}");
		 }
	}
}