Winform RichTextBox Skype like column

Question

I know I can keep a right column open in a RichTextBox by setting the RightMargin property, but is there any way I can insert text into this column? An example would be in Skype where the time is displayed next to the line of text entered. Example

My message of text          5:08PM

Another message of text     5:09PM

If I insert a long bit      5:10PM
of text it should still
wrap normally.