MS give away Pocket Money; I haven't tried it as I use a standard excel template I set up for the same job, but I use PlanMaker (don't need to convert when syncing and it doesn't lose the format) for Excel files as oppose to Pocket Excel.
If you are interested in PlanMaker or its Word equivalent TextMaker check out
www.softmaker.de - they also sell it through Ebay which is sometimes a cheaper option.