Decision reports are saved to the Policy Automation Decision Report table as a block of XML. If the decision report is linked to an existing BO or IO Object, that value is associated with the decision report.
The Policy Automation section in siebel has a deicision report viewer which presents them in a siebel frame as HTML. In order to have a decision report display in the appropriate location you will have to build the UI elements yourself. The Policy Automation section should serve as an example of how to do this.