How to paste raw text?
As Shiki suggested the following steps do the trick:
Win+R
Ctrl+V
Ctrl+A
Ctrl+C
Have a look at PureText.
An alternative method for quickly reformatting text would be to paste the rich text; copy-format (SHIFT+CTRL+C) from any of the raw text you may have, and then paste-format (SHIFT+CTRL+V) over the rich text. This works throughout Office, YMMV outside of that.
Also, [CTRL+ALT+V] is the keyboard shortcut for Special Paste which will allow you various paste options depending on the Office program; including pasting all of the text as unicode, RTF, unformatted, and HTML in Word. This is subject to the User Settings you have for pasting actions (these were set up when the copy of Office was initialized, i.e. "Paste text as original format/new style").