Add Ship to Party in Order

Hi Frds,

How can we add Ship to party at run time. Condition is if ship-to party field is empty i need to copy Sold to party and put it as ship to party default.

I use

CALL FUNCTION 'CRM_PARTNER_READ_OW'
EXPORTING
iv_ref_guid = IS_ORDERADM_H_WRK-GUID
iv_ref_kind = 'A'
IMPORTING
et_partner_wrk = lt_partner

.

By using lt_partner i check the ship-to and sold-to party. if ship-to party not found then i need to make the change.but problem is that i unable to add ship-to party(which is dublicate of sold-to party).

Thanks,

Imran