Skip availability checks on intercompany purchase orders

Hi,

Our scenario is as follows.

We are having APO system linked with our R/3 system for availability checks.

During creation of intercompany purchase order availability checks is carried in APO and as per stock availability PO is confirmed automatically.

Our requirement is that for some checking groups there should not be availability checks on purchase order. Our planner will do stock confirmation in APO as per convenience and then PO will confirm.

We can not remove check box of availability check in checking group because this will impact on all process e.g. confirmation of sales order etc. 

Can you please give any input whether we can achieve this using standard or we need to do this in user exits.

Thanks

Sudhir