ICSC library

I'm using the ICSC library to send commands and data from 1 arduino to another. The question I have is with the ICSC.registerCommand I'm wondering about the char that comes in from the other device to call the function, I'm limited to using only a single char or is there a way to convert it to a string or int? So i Can setup more commands?

You’re limited to a single char, unless you want to modify the library extensively.
By default, the max number of commands is 10, defined in “ICSC.h”, (line 65), but that can be increased to a max of 255, (-128 to 127).

#define MAX_COMMANDS 10