Can't put %username% variable in menu link

Hi there

I'm trying to link from the invite page (domain.com/invite) back to the user's profile page, which they clicked the link on to get the invite page. The user's profile page is domain.com/contributor/username, but having '/contributor/%username%' as the link doesn't work - it just shows the string %username%.

I've also tried [username], [user], %username etc but nothing works. I presume it's because the module itself doesn't support those variables at present.

I'm running Drupal 5.7.

Any help would be much appreciated :)