Expression stats

If someone can help me with two expression stats that I need but don't know how to build ( I had them in PT4)
here are the formulas :
WSD% after river bet =Won at showdown after river bet : Percentage of the time that a player won at showdown given that bet on the river.
Formula: Number of Times Player Won Money at Showdown When Betting on the River / Number of Times Player Went to Showdown When Betting on the Riveraverage saw flop : The average percentage of players who saw the flop over the last 10 hands. (this is very good because it get's relevant very fast and you can deduct how is the table , for example in bounty builders at first levels you will have a lot of people calling so the stat will be 3540, but in deep stages when players are tight it will be 1517 so only looking to that I can adapt my opening ranges) .
Thank you!

Make a regular stat called ‘River Bet’, add a river bet for player and save.
Make an expression stat called ‘River Bet WSD%’, add the following formula 
WonHandAtSDCases(River Bet) / WentToSDCases(River Bet) * 100
Not sure you can do the second stat.