Hey ggofpac,
try "VGTD", as mentioned in another thread on pprune to get the G-load on touchdown. I am not sure if the system records the V/S upon t/d because I think that load factor gives a better indication for damage of aircraft's structure.
Nevertheless I've found a list of alpha-parameters. Check
this link.
Also catch a view on a
previous thread treating the topic...
I hope I could help you
best regards from Austria,
Luke