Specify host for a playbook task

Is there any way to override the current host for a given task?

I want to set up a recurring database copy, so I need to run some commands within a playbook (all of which apply only if a variable is turned on at the command-line). This sequence would begin by dumping the source database and copying it, so it needs to be a different hostname from the one being processed. I tried “host” “hosts” “hostnames” but none worked.

delegate_to:

Thanks!