Tracking capital gains and losses

Does anyone have a good system for tracking mutual fund capital gains and losses?

I sold some non-registered funds recently, some at a gain and some at a loss. I know I can only use losses against capital gains. The fund companies don’t provide this information so we have to track it on our own. My statement shows book values, which are not always accurate.

What’s a good way to accurately track fund book values, given that they change from the statement date to the date of the sell, plus the value on the trade date? I'd prefer not to use a spreadsheet. Just some good manual system.

Thanks.