How to use custom service while extending standard SAP fiori app.

Hi Experts ,

This is regarding SAP WEB IDE fiori standard app extension,

The requirement is to extend the  Standard App MY QUOTATIONS( SD_MYQUOTES) with one field like Long text  at header and Item level.i have done the view extension with text area by using web ide tool and created service (Z_LORD_MY_QUOTATIONS_XXXX) in the backend SAP system and i have extended the required entityset Quotation headerSet with new field.now i want to use custom service along with standard service calling in the Component.js.

How to use custom service for extend standard app. Can anyone guide me to achieve this functionality .

Thanks .

Regards,

Sekhar.