How to change the approval link's string in workflow?

Dear sir/madam,

         I want to change the descr in the last step to the user_role's description,like the screenshot:

        

        When I trace the peoplecode, and find the method 'outputHTML' in EOAW_MONITOR.MONITOR.approverInfolink,.

        Here rely on the length of the user list to judge,if len=1,then return username,otherwise return multiple approver.

        But I need the parameter %this.step.step_nbr,and need to judge the condition %this.step.step_nbr=&last_step.

        And When one of the multiple approvers click the button--'approve',the link string need to keep its name be it's role description.

        Anyone can help me?