RichTextBox C# Set caret location winforms

Question

I am building a chat application where the user enters its text to a richtextbox.

In the rich text box there is an initial text which says: \"Me: \".

Now, when

Answer 1

Found it googling on the property SelectionProtected

richTextBoxUserText.Text = INITIAL_TEXT;
richTextBoxUserText.SelectAll();
richTextBoxUserText.SelectionColor = Color.Red;
richTextBoxUserText.SelectionProtected = true;
richTextBoxUserText.SelectionLength = 0;
richTextBoxUserText.SelectionStart = richTextBoxUserText.TextLength + 1;