Service Call: Saving a document into the Expenses Tab

Experts,

I have a client who needs to save 1 Sales Order to Multiple Service Call Expenses.

I have looked over the ORDR table to see if I can create the link there, but did not see the link there.

I found the link on the OSCL and SCL4 tables, but these are only populated if you enter the document through the Service Call Expenses tab.

Is there a way to update this link after the Sales Order is created?

Can I link 1 Sales Order to multiple Service Call Expenses?

I have found that this is not possible without customization, am I correct?

Regards,

Marli