in reply to bc.exe - trivial one-liner
What is pp?
I have a similar widget, it's a perl script that reads the clipboard, evaluates each line, and stuffs the results back into the clipboard again. You can find it at Clipboard transform keys. I write my expressions in Notepad, and have the script bound to Ctrl-Shift-* so I just cut the lines I want evaluating, hit the keys, then paste the results back into the notepad.
In Section
Cool Uses for Perl