How can project details be updated on Open PO's

Hi,

There is one requirement from my client. They are using Purchasing module but now we are offering them Project Costing module as well.

So we want to update the Project details (Project Number, Task number, Organization etc.) on Open Purchase Orders.

Is anyone know how we can achieve this.... from front end Or we can achieve this through back end Or do we have standard API for this activity?

Regards,

Vinayak