FMS on Header Level Field in SAP b1

hi,

I want to add FMS on header level in SAP b1 (OOEI) table

for example :-

i want to calculate Linetotal + Tax Amount +(Freight Amount from Base Document Table)

i got LineTotal & Tax Amount field from OEI1 table  but how to calculte fright amount(DLN3) from Delivery(ODLN) table.

please help me for solve this type of Query .

myQuery is like that -

select $[OIEI.DocTotal.Number] + (select SUM(LineTotal) from DLN3  where DocEntry = (select DocEntry  from ODLN where DocEntry = $[$38.45.0]))

pleaserly me as soon as possible.

Thanks