Send Email using different from address

[freeman642]

I want to send an email from a different account that the user is
logged in from, so logged in a usera, have permissions and send of
behalf of rights to send from userb. Open an email, how do I change
the from address to userb in VBA. No entity under Mailitem properties,
tried sender but seems only used on emails already recieved.

Any ideas gratefully received.

Thanks, John