tamte

- you can export it as alembic (make sure Polygon Selections is checked)

- in Houdini import using Alembis SOP (or Alembic Archive, whichever you prefer)

- then when you unpack desired object you will see your selection on the geo as a group

try Divide SOP with maximum Edges 4
since some softwares may not be able to handle n-gons with bridges

but without seeing it it's just a guess

VisionaryMind
what do I do when a node shows a yellow exclamation point?

MMB on it to read the message