Check the syntax very carefully, it very sensible to spaces, case sensitive... Have you tested already using the windows performance tool ?, check twice the spelling and the uppercase, points... If the CPU works, that should work if it's valid.
I have set up the following module;
# Lotus Domino Availability Index
module_begin
module_name Domino_AI
module_type generic_data
module_perfcounter \Lotus Notes(Server.AvailabilityIndex)\Notes Statistics
module_end
But nothing is appearing in the agent. I tried the example % Processor and this works fine, as do other general counters, but I can get no Lotus Notes counters to work. What am I doing wrong?