[netwolf]

There are two issues here.

1. Goto an object and track it.
2. Countering the Earth's rotation by Polar alignment.

What you need to do is duplicate Meades Fork mount Autostar system.
With the meades you can work in Alt/Az with Goto and track an object for viewing. You can also do short exposures of planets. However if you want to do DSO's then you have to add a Wedge to the Alt/Az mount.

Imagine tilting your Dob base so that it is aligned with the South Celestial Pole (about 11 degrees of from Earth's magnetic pole). The CP is the pole on which the Earth rotates. But just puting it on a wedge is no good you need to then rotate your dob on this wedge to counter the earth rotation. With the Meade fork mounts, you just tell your Alt/Az software that your polar aligned, and it makes the Alt/Az movement such that it counters the polar rotation.

The concept of the SCP or NCP (north celestial pole), and alignment to these seems mind bogling to the begineer. But there is a lot of good websites out there that show you and explain to you what this is better than i have tried to do..

Regards
Netwolf.