insideseam

i'm trying to figure out how to access a control panel (on pstn) from my computer (on internet), and then 'converse' w/ the panel via some vt100 terminal emulator (like hyperterminal or telnet). if i had a land line to my computer i could use hyperterminal or some such, but i'd like to avoid getting a line installed. would this software be able to support this type of call? if not, do you know of other software that would? thanks for any help/direction. (i know next to nothing about this stuff, so i apologize if this is the wrong place to ask or if the whole idea is dumb)