I generally use Google Finance to track individual portfolios, but since it doesn't have a compare feature, I made an excel file to do that, as well as to check the asset balance.
Basically, the 2nd and 3rd sheet only require copy-pasting the data from the spreadsheets generated with google finance, while the 4th sheet currently requires manual input.
Maybe there's a better way to do that, so far, I'm updating it myself.