Is there a way to communicate to a N30 over ethernet using any vt100 emulation and be able to control the n30 the same as direct connected to add and delete points?
Unless you have something connected to the serial port then no. The ethernet port does not support VT100.
The only thing which would work is a Black Box device which connects the RS232 to etherent.
I have used the Lantronix uds10 in the past and it works well.