Alert for release hold with line number

  I have the alert for release hold but is planning to update it to alert on the specified line number, when the line number is being released.  How should I set the action sets and  action so that when the 
1.SO is released in header, an alert with only SO number sent, without each line having the alert, 2.Specified line released, an alert for the that line sent. 3.Multiple line released, an summary alert with the lines sent.
I know it is a trigger event, is it possible to achieve 3?  


 select distinct oh.ORDER_NUMBER,  RCUST.CUSTOMER_NAME, rcust.CUSTOMER_NUMBER, DECODE(HOLD.LINE_ID,NULL, ' ',                     ol.line_number||'.'||ol.shipment_number) LINE_NUMBER INTO     &order_number  ,&customer_name  ,&customer_number  ,&LINE_NUMBER from ont.oe_order_holds_all hold,  OE_ORDER_headers_all oh,  OE_ORDER_lines_all ol, ra_customers rcust, oe_transaction_types_tl tyl where  --hold.HEADER_ID=185433  hold.HEADER_ID=oh.HEADER_ID and hold.HEADER_ID=ol.HEADER_ID and hold.ORG_ID IN (86,457) and oh.ORG_ID=ol.ORG_ID and hold.ORG_ID=ol.ORG_ID and hold.RELEASED_FLAG='Y' AND oh.sold_to_org_id= rcust.customer_id and oh.order_type_id = tyl.transaction_type_id and tyl.NAME in ('SW MACAU CONTRACT','SW SALES CONTRACT','WHOLESALES ORDER','LPHK WS BACK-TO-BACK ORDER') and hold.rowid=:rowid