Compensatory Leave Request Workflow

Hi All ! When ever a compensatory request is submitted a leave Allocation is auto created. The scenario i am facing right now is i have added compensatory leave in my leave policy and in allowed i mentioned 10.
But when a employee submit a CLR leave Allocation is done on Pro Rata Basis from work_end_date to leave period end date. what i want is to allocate only those leave against for which CLR has been submitted. Example if leave request is for 2 days, 2 leaves should be allocated.
Any Help in this regard will be helpful.