supporting steel cantilever with an 30 yr old concrete column

[fecal]

I have an existing 30 yr old, 5′ by 4′ concrete column of which I propose to join a steel beam to (adjacently), to create a platform. I’ve thought of using “rawl bolt” to join this beam to the column but suspect that crack may develope and subsequent failure. No space is available for an over-head column nor a column underneath, how could u assist me in supporting this beam. Your advice would be grately appreciated. Thank you