Regular expression to get last 12 characters of a string (exept spaces)

I want to use a regular expression to capture last 12 characters of a string exept spaces.

2 exemple :

• COD83 8365 838 BF => D838365838BF
• COM2893 0409 7642 946 => 304097642946

In c# code, I want to use this :

var input = "COD83 8365 838     BF";
var pattern = "";
var replace = "";
var result = Regex.Replace(input, pattern, replace);

Console.Writeline(input); //print D838365838BF

I read this article but don’t achieve to adapt for me : Regexp to match all the characters except spaces and 4 last characters

Can anyone helps me ?

>Solution :

This would probably be easier without regex.

var input = "COD83 8365 838     BF";
var noSpaces = input.Replace(" ","");
var result = noSpaces.Substring(noSpaces.Length - 12);

however if you wanted plain regex this would work

var input = "COD83 8365 838     BF";
var pattern = ".*(\\w)\\s*(\\w)\\s*(\\w)\\s*(\\w)\\s*(\\w)\\s*(\\w)\\s*(\\w)\\s*(\\w)\\s*(\\w)\\s*(\\w)\\s*(\\w)\\s*(\\w)\\s*$";
var replace = "$1$2$3$4$5$6$7$8$9$10$11$12";
var result = Regex.Replace(input, pattern, replace);