It's all a bit relative depending on the performance you're expecting (some people wouldn't be caught dead trying to use *any* laptop as their primary editing machine, and some people edit on MacBook Airs).
To get us in the ballpark, what kind of a Mac are you used to using? Have you edited video on it?
Do you know some of the specs on the Lenovo Ideapad that you have?
1st, the hardware sub-forum http://forums.adobe.com/community/premiere/hardware_forum?view=all has a LOT of discussions
2nd, Laptop Video Editing PC discussions
3rd, running PPro is not the same as USING PPro
-everything is related to what kind of video you want to edit
John has made a good point. We used to edit DV on really old machines and it worked. It still will. But editing HD is another matter. And editing multicam sequences is another. Straight edits are generally no problem, and then adding color correction changes everything.
edit: Oh, and to answer the other question, any PC that can successfully handle Premiere Pro is easily brawny enough for Microsoft Office.
[Moved to hardware forum.]