@Kiara Just trawled the web for a moment.
Looks like in Unity the method is Pd.SendMessage() and in Pd a [receive] object...... but the [receive something] object requires a name.... an address.
Maybe you simply prepend the address to the array data on the Unity side i.e. Pd.SendMessage("something" 5 4 3 2 1) .....but I have no idea.
David.

Based on the documentation, I should be able to send message box values using the following method

public void SendMessage(string destination, string symbol, params object[] args)

I know, destination = receiver box with a string name and args = array. I can't figure out what the "Symbol" parameter means, and without it, Unity is using its own Send Message method instead of libPd.