Axleshire, make yourself a little chart for 'your' use year. Then it's easy to see how it works. For March, it looks like this:
YEAR.....Use Year......Use points during this timeframe
2001....Mar 2001.....Mar 1, 2001 thru Feb 28, 2002
2002....Mar 2002.....Mar 1, 2002 thru Feb 28, 2003
2003....Mar 2003.....Mar 1, 2003 thru Feb 28, 2004
2004....Mar 2004.....Mar 1, 2004 thru Feb 28, 2005
2005....Mar 2005.....Mar 1, 2005 thru Feb 28, 2006
You can bank points from any year into the following year. You can borrow points from any year into the prior year.
In your case, you want to bank your 2002 points into the 2003 use year. You also want to borrow your 2004 points into the 2003 use year. This then gives you 300% of your points all in the 2003 use year of Mar 1, 2003 thru Feb 28, 2004. This then covers your Jan 2004 trip.
You have it right. Maybe the chart just makes it a little easier to 'see'.
Hope this helps