.NET Format a string with fixed spaces

Does the .NET String.Format method allow placement of a string at a fixed position within a fixed length string.

"           String Goes Here"
"     String Goes Here      "
"String Goes Here           "

How is this done using .NET?

Edit - I have tried Format/PadLeft/PadRight to death. They do not work. I don't know why. I ended up writing my own function to do this.

Edit - I made a mistake and used a colon instead of a comma in the format specifier. Should be "{0,20}".

Thanks for all of the excellent and correct answers.