RICHEDIT20 SetSel

I use CRichEditView.

My application works as follows..
1. Get Text buffer from CRichEditCtrl::GetWindowText(CString& str).
2. I find some token and modify in str(CString class returned by GetWindowText)
3. Set Selection to Richedit by index of CString class (zero-based).

when I used Richedit1.0, the selection range was perfect. but
when I use Richedit2.0, the selection range is difference between CString and
RichEditView...

in my thougt, CString which is retrieved by GetWindowText() doesn't have '\r',
but the RichEdit has it...

How can I do?