String To Function And/or Listbox?

i wish to make something similar to a command-line kind of thing in which one can type a series of words and the program will run the string through a function that splits up the words uses the first word string to find which function needs to be run and makes the other word strings as parameters of the function to run. its kind of like a odd interpreter based scripting language however once this problem is addresed i have a seperate issue.

i then need to output to a new entry on a ListBox that would be named as a parameter of the first function that splits and such that i explained above.
however i do not know of what i can use to input the name of the listbox only then have that add an entry from within the function.

i wish to do it this way so as not to be tied down to the same naming conventions of the list box every time i use it.

in the end i would like to main function to do all of the above and be called simply like this: Comand2Function(inputstring, outputlistbox)