If objInsp.EditorType = olEditorWord Then Select a block of text while composing a message and run the macro.
To use, open the VBA Editor (Alt+F11) and paste the code into a module. I tested this macro in Outlook 2010 and Outlook 2013 it should also work in Outlook 2007.
See How to use Outlook’s VBA Editor for help using the editor, setting security levels, and signing macros.
