Did you get what you need? Basically you would build the List box using the Split() function that the old dude suggests. Do you know how to build the list from the array?
Then to take the values back into the field, you would check the field for any existing values. If yes, then add a comma and load in the one or many selections from the list box, and if no, just load in the one or many selections without the leading comma.
Let me know if you need the code. If so, I am assuming a bound form, post the column names for the incoming and outgoing data.
Look it up at: http://wrox.books24x7.com