Sales order line item check based on material status

Hi

I have the following requirement

There are Distribution chain specific material status maintained in the material master ( Sales Org1 View). Now for some of these statuses we need to reject these items in the sales order @ line item level. A reason for rejection needs to be assigned for these line items.

Is there any standard setting or a user exit is required. I believe user exit save_document_prepare could be used to carry out these checks & assign a reason for rejection. Pls suggest asap

Thanks

Ramesh