How to record Inbound Receptionist calls?

I have a front desk with 4 girls that answer between 400 and 600 calls a day.
I need to record those calls, but not the down-line conversation.
I have an inbound route that hits a call flow control, (So the last person out can manually activate night mode) then hits a queue which all four girls are agents of.

I need to record the call only while the receptionists are speaking with the callers… not after they are transferred. I do not care what greeting/ringing is also recorded.

How can I accomplish this?