This is the question asked most frequently by beginners. The answer of the experts is always the same: Don't do this.
This is exhaustively explained here: TUTORIAL: Why and how to avoid Eval
Do not hide an index in the name of a variable, but use an array and an index:
brC = cell(1, 50);
for k = 1:50
brC{k} = cell2mat(br(k));
end
This is some pseudo-code only, because it is not clear, what the contents of your variables is.
