Hello @klaudiac , do you have the host list with you? Also, is it like a partcular time only a particular host needs to be searched? If so, does this change with time - ie, at 6 PM today Host XXX needs to be checked while at 6PM tomorrow Host YYY needs to be checked?
If its just simple search from a list of host which you have to begin with you can use :
index=console1(sourcetype=c1:agent OR sourcetype="c1:agent_registered") host IN (hostname1,hostname2..) | stats count by host