You can run single command in a container using the following:
vzctl exec 201 service httpd status
How to find out all the VZ containers:
vzlist -a
The other way? Yes, there is. VZ list is stored inside a file /proc/vz/veinfo, and we can use it with the help of shell to run command in each VZ as following:
for i in `cat /proc/vz/veinfo | awk '{print $1}'|egrep -v '^0$'`; \
do echo "Container $i"; vzctl exec $i <your command goes here>; done
An example, can be the following:
for i in `cat /proc/vz/veinfo | awk '{print $1}'|egrep -v '^0$'`; \
do echo "Container $i"; vzctl exec $i service httpd status; done
This should show all the httpd status of the VZ.