Oh, what the ...
Let's see, from the Adventures:
1 - The Kinuir
3 - Twilight's Peak (actually in Rhylanor subsector, but does involve Regina subsector)
12 - Secret of the Ancients
The Short Adventures:
1 - Annic Nova
1 - Shadows
2 - Across the Bright Face is on Dinom in Lanth subsector, but is just outside Regina subsector.
7 - A Plague of Perruques
The Traveller Book is "set" in the Regina subsector, and includes two adventures there:
- Shadows (same as Short Adventure 1)
- Exit Visa
JTAS had bunches:
1 - Rescue on Ruie
8 - Dagger at Efate
8 - Crystals from Dinom (again, in Lanth, but close)
9 - Rule of Man Commemorative
23 - The Birthday Plot
27 - Grandfather's Worlds
And the Introductory Adventure starts on Regina itself.
OK, I'm done. I am sure I missed a few, but these should give you a headstart on your own efforts.