Hello everyone.

I am wondering about a thing. Fx if I have this box:

Attachment 196254

and i want to take the the first corner where the red arrow is, and stretch it out to the blue circle i made. And furthermore I want to take the second red arrow and stretched this point out to the other blue circle. How can I do that? I am not very good at Rhino yet, so when I model something, and it dosent match what I want, then I am forced to start over. I would really like to learn how to manipulate a 3d figure, so i can drag each point out, so I can get the form i want.

Hope you can help me?
Best Regards
Mads