HELPPP --- function input is String which is name of another respective function

I want to implement function :

function m=matlab('learn')
%something here
end

Above, string of learn must be the name of respective function which is written in another matlab file .m | I have 2 problems

1) when I want to pass string of 'learn' as input to function, it throws error.how to handle this

2)if I solve problem 1., how can I call respective learn function from another matlab file?