What's "tricky" about it? If it's about the governance and setting up a CIC, the charity team at most firms would be able to do this? Why does the firm need to be in London? Having said that you could try Andrew Studd at Russell-Cooke - https://www.russell-cooke.co.uk/people/andrew-studd/ - depending on the complexity, he would find the right person in his team.
What's "tricky" about it? If it's about the governance and setting up a CIC, the charity team at most firms would be able to do this? Why does the firm need to be in London? Having said that you could try Andrew Studd at Russell-Cooke - https://www.russell-cooke.co.uk/people/andrew-studd/ - depending on the complexity, he would find the right person in his team.