Custom Sales Order Workflow by Adding Specific Program to hold price, restrict ship to location etc

Dear Guru's,

There are some requirement from user to add checking before booking sales order, example if price different between unit selling price and list price,

certain margin amount of sales order, and specific ship to location. If sales order fall under the condition, it is must hold status. Now program has been defined to hold

but it is possible to add in sales order workflow? After user click SAVE or booked then the program will triggered, any input and documentation will be helpful

Regards