get a builder in to check what you want to do, load bearing walls should only be removed by people who know what they are doing.

Load bearing walls can not be removed without an rsj being put in its place to take the weight of the building above a pillar would not be sufficient to spread the weight effectively and could collapse if incorrectly done you would need a builder with a structural alterations back ground to avoid there being issues in the future.

As suggested get a builder involved but it is not so easy to just leave a pillar unless the pillar is supporting the rsj.
A bearing wall goes from the ground floor to the loft so if you remove part of the wall at the ground floor the bearing wall has to be supported with a sized rsj.
Even if you do a simple aperture a rsj has to be used.