Query help needed for Sales order panel user field query.

I have a user defined form field on sales order row level called = U_DEPFEEAMT

1, I would like this field to get the value from a field on this sales order row level multiplied by what is in point 2 below. The details of field in point 1 is :

Form=139, item=38, pane=1, column=10002117, and row=1

2. The contents in field 1 should be multiplied by a value coming from another user field linked to OITM master item.

The details of user field attached to OITM is :

OITM.U_DepositFeeON

Appreciate your help.

Thank you.