Hi Jet,
This is not something you can currently do on the farm, as there is no way to retrieve information from past results from a current run of the experiment
The closest you could get is check the value of __counter_value_from_server__ which, in the absence of a SetCounter in your experiment, will get incremented only when you receive a submission. However, it could still be that multiple participants open your experiment before the counter gets incremented to the cap value, and all those participants will still take your experiment and submit their responses
Jeremy