If you want to assign leads to a specific agent, do the following:
1. Make a filter view of the leads A phoner must be assigned.
You can find help for filter view here:
Data Filter
Campaign Filter
2. Go to the filter and add an action by selecting "Actions":
3. Select the action "Edit/move leads" followed by "Assign to user" where you choose which agent to assign the leads to. Finally, select "Execute action":