Really can't tell you without pictures showing the wall in question. If you really want to hide it, and it is up against the foundation, use either 2x6 or 2x8 on that wall, same if it is in the middle of the room where a wall will be.
is it a tube or a pipe? Is it a kitchen wall? I only ask because if you're mounting cabinets to it, it would be better to attach your king studs to the column if possible. Mrgins is right, just attach to it if possible. Otherwise, don't attach to it, but be sure the wall is secure at the top and bottom...and span your drywall over it, centering the post on the drywall. Then finish the rest of the drywall from the center piece. That's what I'd do.