Upon receipt of a referral, the child support enforcement unit of the social services district will determine which actions are necessary to secure child support, including establishing paternity, if necessary. Where no support order exists, the child support enforcement unit of the social services district will petition the court for an order of support pursuant to the child support standards as set forth in section 240 of the Domestic Relations Law and section 413 of the Family Court Act. Where the basic child support obligation as determined in accordance with the child support standards exceeds the costs of care as set forth in section 422.5(d)(3)(i), (ii) and (iii) of this Part, the child support enforcement unit of the social services district may advise the court that the basic child support obligation is unjust or inappropriate and that the amount of support ordered to be paid should not exceed the actual costs of foster care plus any costs attributable to the costs of medical assistance paid on behalf of the child.