Replacing posts under beams
I am in the process of moving an exterior wall in the basement. The house is post and beam construction. The wall being removed has two posts in it that hold the upper floor. I need to leave the beams supported where these posts are. When I took apart the wall to see how it was put together I was surprised to see that there are 4 2x4's (spanning this 16' long section of wall) stacked between the posts and the foundation (which is a block foundation). As the posts will no longer be inside a wall I need to come up with a way to keep the posts in place by themselves.
The existing posts are wood but I am considering replacing with steel ones. My problem is how do I interface between the existing foundation and the new posts in such a way that the bottom of the post cannot kick out. I assume the stack of 2x4's was there to spread out the load from the posts onto the block foundation. Is there a way to connect a steel post to the block foundation such that a slab can be poured around the posts? Do I need to put a steel plate on the top of the block spanning the two posts and then anchor the post flange to that? Should I build up a section of concrete to replace the stack of 2x4's and then secure the posts to that?
Any help given would be GREATLY appreciated. I can post pictures and drawings if that helps.