I've set up a button on my toolbar to handle this. In Contact view, right-click on the toolbar, then click Customize. Go to the Commands tab, and click on Lookup. Scroll down to Company (not Companies), then click and drag it to the toolbar. Once you click close, you'll be back at Contact view, and will have the button available. You can do the same thing in any other view. I've done this for Last Name lookup in Contact and Calendar view, and use them all the time.