Simply make your advance Magical Express reservation for morning of your check in day at roughly the time you will be down at the welcoming area ready to go to your resort.
To speed up the reservation process, have in mind a flight, any flight, any airline, arriving in Orlando at about that time. The DME reservationist CM may or may not ask for that.
It is not necessary to have your magic bands (bracelets) or My Disney Experience or on line check in done in advance for this.