centre one of multiple inline/floated elements

centre one of multiple inline/floated elements

I already know how to centre things using margin:auto or text-alight:centre.

Suppose you have a div which has multiple inline/floated elements.

One of these is always present and is called object A.

To the left of object A there is always one object.

To the right of object A there is a dynamically generated list of other object, there is an unknown number and always at least 1.

Is there any easy way to centre object A ether in the centre of the available space (so it is equidistant from both of its neighbour elements). or in the centre of the parent element (regardless of the positioning of the other siblings)

clearly the standard margin:auto or text-alight:centre wont work.
would something involving floats work?
what about use of absolute positioning?