Availability Check for sales order quantity that should be split for two schedule lines

Dear SAP Experts,

My Client have a Business Scenario,its a make to stock scenario

system settings :

Checking group 01 Daily requirements

Checking rule A

Requiement type KSL

Requirement class 030

available quantity 30

Sales order quantity 50

Now in sales order showing two schedule lines ,showing one schedule line with current date zero confirmed quantity , and one future date showing the confirmed sales order quantity as 50

Now the requirement is

the first schedule line -curent date with available quantity as 30

Second scedule line -future date with remaining 20 quantity

how do i configure -please guide me gurus

With regards,

Pratheep