FM to update custom fields (extended structure CI_EQUI) in table EQUI?

HI,

My requirement is to create a device/meter programmatically and update 'Z' custom fields in table EQUI include CI_EQUI in the table.

I have two requirements

1. How to create equipment or any FM to create equipment (as we make it in IQ01, I have to do it do it programmatically)

2. Is there any FM to update custom fields (structure CI_EQUI)     

Help me if anyone has worked on similar requirement or have any knowledge on this.

Thanks,

Amey