change initial form

Hello,

  I have ops portlet which is displaying several links to different xform applications. I would like to implement the functionality that will when user goes to other portal page and returns back, "redirect" him to one of these xforms (just as it would happen if he clicks on one of these links). To which page it will be redirected is based on external variable (e.g. obtained from database).
Does somebody knows elegant solution to this problem.
thanks.