How to read Freight order data using only Freight order No.

Dear TM Experts,

I need to develop a custom proxy to update delivery quantity and 1 Z field of SAP ECC back to SAP TM. I am having a freight order in hand using which I need to read freight order root data. Also, let me know is their a way to call method modify (/BOBF/IF_FRW_MODIFY) and read (/BOBF/IF_FRW_READ) and in my custom code using which I can read and modify freight order data.

Thanks in advance.

Regards,

Md.Rafi