Affiliate Marketing Secrets

I will be visiting a religiously-affiliated school today for a meeting and as is customary, will likely be asked to lead a quick group prayer before we begin. I’d like to thank my hosts, wishing us all great health, happiness, and guidance as we venture forth together but I’m unsure of how to begin the prayer…
I recall from previous experiences of this nature, the person leading the prayer saying one short phrase beforehand (I believe addressing God), the group repeating back something along the lines of, “…And to you as well…” and then the prayer getting under way.
My question is, what is that brief line the prayer leader says beforehand, and is that even necessary? I certainly don’t want to offend by beginning the prayer in the wrong fashion if there’s a specific line I’m to say beforehand.
Thoughts?
But I specifically remember group prayers of this nature beginning with a quick line by the prayer’s leader, I believe to the The Father, and then the group repeating back “..and with you..” before the leader of the prayer continued. Any recall what that brief introductory line is?