Note: This stat won't take into account things like happy hour; there's really no good way to do that perfectly at this point, especially since there are often unscheduled happy hours.
Note #2: This stat will be for cash games; you'll need to make a separate one for tournaments, but the steps will be nearly identical. See
this tutorial if you need more assistance.
As you said, FTP points = amount of rake taken from hands you were dealt in. Click Configure --> Configure Statistics, click on Holdem Cash Player Statistics, click on the Columns tab and click New.
Give it a title (say amt_ftps), and the following expression:
sum(holdem_hand_summary.amt_rake)
Give it whatever description you want.
amt_rake is the amount of money paid in rake per hand. (You can't use the column amt_rake because it checks to see if you won the hand first, as amt_rake is the rake you yourself actually paid.)
Click on the Stats tab and click New. Give your new stat a name and description.
You want to use the value expression: amt_ftps
On the Format tab, give it a title (FTPs), a width (which you may want to be as high as 70 or 80 depending on what sort of report you want to use this in), and the format expression /%.2f
Add whatever categories you like, save, update your cache, and you should be all set. You can use this stat in the HUD or in any report using the HCPS section.