Mezzanine support

[cavendish]

I'm buying a property with a mezzanine built in a ground floor room. The room measures 12ft x 13'6", the mezzanine is at 7'6" above ground, runs for the 13'6", is 5'6" deep and currently accessed by a ladder. Main problem is the lengthways joists are supported by a wooden beam coming from the back wall to a brick pillar which stands virtually in the middle of the room!
I'm wondering if it's possible to replace this with say two steel joists in an inverted L shape at 4'6" and 9ft along the back wall? The steel joists would need to be 7'6" x 5'6". Would this be practical and if so would I have to have the joists welded or could they be bolted? The mezzanine could possibly have extra support from exposed joists in the ceiling. I realise I may have to consult a structural engineer ultimately but wondered if the idea is feasible or a non starter.