Hi and
to IceInSpace!
The DSLR will do just what you need - but you just need to control it via your computer/laptop rather than at the camera itself which I agree, is a pain to try and squint through the viewfinder and look at the LCD display.
What you need is software like ImagesPlus (and others), which allow you to control the camera from the laptop. You can use it to focus, and to take short and long exposures, and download the images directly to your laptop. You may need a special cable or two to control the camera, and maybe a different one to take long exposures - it depends on the camera.
Cheers