Apply mask a string in C# asp.net?

[XxSharpShooterXx]

Hi all in my project i want a currency in three formats,.\[code\]1) ...999,999,9992) ...999,999,999.003) ...999,999,99\[/code\]The format is specified in mysql data table field. My project is in ASP.NET so I can't use MaskedTextBox . Code I tried:\[code\]String.Format("{999,999,999}",rate);\[/code\]and \[code\]rate.ToString("999,999,999).\[/code\]How to get the mask string?