Removing or replacing a post supporting a bolted joint in a long glue lam beam
You have a lot going on at that point in your roof. I would strongly recommend you get a civil engineer to have a look if you are considering removing the post.

If you only want to replace the post with a steel column, that would be simple. You can google the strength of a wood column in the dimensions you have and select a similar or stronger steel pole.

From the picture I can confirm that it is a load bearing pillar, the beam that stretches from the windows toward the 4 x 6 vertical timber is transferring it's load to the timber.