Pasting RTF into a RichEdit as plain text

I'm using a richedit as a text editor, with the plain text property set to
true to stop any rtf being loaded in. However, I've found that if you paste
text from another program (eg MSIE), the text is inserted into the richedit
as RTF, and only saving and reloading the file will turn it back into plain
text. How can I get around this?

Also, if anyone has any ideas on how to implement syntax highlighing in a
richedit, I would appreciate hearing them!

Ian Gregory