How to call a procedure through form personalization

Argument

='begin

CUST_ORDER_DFF('''||${ITEM.DLVB.SOURCE_HEADER_ID.VALUE}||''','''||${ITEM.DLVB.SOURCE_LINE_ID.VALUE}||''','''||${item.dlvb.source_header_type_id.value}||''','''||${item.dlvb.customer_id.value}||''','''||${item.dlvb.attribute9.value}||''');

end'

In above statement only single quotes are used i.e (')
The above used can be get through Insert 'Get' Expression as per below screen shot.
By pressing ok button we can get the generated statement.
The procedure example is also mentioned under the screen shot.

CREATE OR REPLACE PROCEDURE APPS.CUST_ORDER_DFF( p_order_header Number, p_order_line Number,p_order_type  Number, p_cust_id Number, p_dff varchar2 )
AS

BEGIN

--Do your work here

 END;
/