Scripting...scripting is fun.
Ken is right, if you've already done something that got you the results you wanted grabbing the script from the history is the best. This is especially true when you're just playing around and experimenting. A side I don't think many people consider. Most people I know fool around and try to remember exactly what they did, then try recording the script from scratch.
To record a script as you're working, is very simple. First you need to make sure you have your script toolbar open. Go to the View men -> Toolbars -> Script
On the script toolbar you'll see a big red dot (unless you don't have colored icons turned on

) just hit that to start recording your script.
It won't record Undos, so you don't need to worry about that. It will simply record all of your actions as you begin to edit the photo. There is actually an official Corel webinar given by one of the members on these forums, Cassel, on the basics of scripting if you're interested.
http://www.youtube.com/watch?v=IOT2k2wlCG8
Also I didn't see a response to your question about selecting the white point in the White Balance dialog. So forgive me if this was indeed already answered. So you select the White, Black, or Gray points by using the preview windows inside the White Balance dialog. If you can't see the Before and After previews you'll need to click on the "Preview" text in the upper-left of the dialog. This will open up the preview windows. In the left "Before" window you'll be able to zoom in and pan around the image to select the spot you want to identify as "White."