asterik in the outlook rules to pick out all forms of words?

I want to set up more rules under the "rules and alerts" in Outlook 2003 to
pick out and delete spam containing certain keywords in the subject. As you
know, the senders can be tricky in putting different forms of word to try and
defeat junk mail filters. For example, if I wanted to have a rule that
picked out all e-mail with any form of the word "invest" (investor,
investment, etc.), can I use an asterik (i.e. "inve*") in the rules wizard?
It works sometimes, and others it does not. Is there some other character
now in use as a wildcard?