MS Word can also count the words in part of a document. Turn on the Word Count toolbar (right click on a toolbar and select it from the menu). Select the text and click on the "Recount" button. Or select the text and go to Tools>Word Count from the menu. You will get the count for the selected text instead of the whole document.
You could also get a freeware text editor that will count the words for you, such as
Notepad XP. Copy the text you want to count and paste it into the text editor for counting. Afterwards just close the text editor and don't save the copied text.
There is a website
here that you can paste your text to and it will count the words for you.
I'm sure there are some utilities that will run in the tray to do this also, like
Text Tally.