How to move the cursor to the correct line in a RichTextBox

I'm sure there is a really simple way of doing this, but this works out for me. Please write a comment and tell me how it's supposed to be done if this isn't the best way (which I'm sure it isn't ;)

public void SetCaretLine(int linenr)

{

      if(linenr > this.richTextBox1.Lines.Length)

      {

            MessageBox.Show("Line " + linenr + " is out of range.");

            return;

      }

      int row = 1;

      int charCount = 0;

      foreach(string line in richTextBox1.Lines)

      {

            charCount+=line.Length + 1;

            row++;

            if(row == linenr)

            {

                  //set the caret here

                  this.richTextBox1.SelectionStart = charCount;

                  break;

            }

      }

}

Well? I guess there's a win32 api lurking in the shadows that does this in 1 or 2 lines of code - then show me already!