OK Len, you now need some advice from the electronics/computer experts here.
There is probably a cheap device you can buy which will take in a voltage, transfer it as data into the computer via a USB port and have some software to display that and store it away.
Controlling the telescope is a bigger question. You would have to add motor drives to each axis, then could have some software that allows you to control those motors - $s and DIY needed.
Good luck.
