GPO in Finale 2010

So, in Finale '10, which comes default with Garritan Orchestra, I'm trying to figure out how to layer multiple samples into the same staff line. One of the features is that when you are assigning parts for your score, you have the option of selecting (for example) "Flute Solo", "Flute Player 1", "Player 2", or "Player 3". Flute Solo is the original recorded sample, and the 3 players are all derived from the solo sample, but they have been tweaked so that if you have all 4 samples on different staves play a unison note, the slight adjustments in the tone and timbre of each sample makes it sound like there are 4 different flute players, to give the more realistic effect of a full orchestra, as opposed to the unison pitches for multiple staves of the same instrument turning into a singular flute sound, as if there is only one flute playing.

My issue is in the score and playback. I'm trying to get this effect of multiple players for playback reasons, but I don't want to have to create 2-3 different flute staves to get this effect. And the problem is the same for 2-3 clarinets, 2 oboes, 2 bassoons, etc etc down the line. I could get the sound I want if I created a score with 30 staves. But that would take up a ridiculous amount of space and power, and take forever to load every time I opened it.

My question is, is it possible to assign multiple samples to one staff, or perhaps assign different samples to different layers on the same staff, to get the effect of multiple players even in unison passages, so in playback, i still get the sound of a full orchestra?

Thanks in advance if anyone can help. Much appreciated.

Window -> Instrument List. At the name of the staff name is a dropdown menu enabling you to connect different instruments to separate layers

Awesome, thanks Jcramer....one other question, is it possible to do this in the setup wizard, so the document is created correctly from the get go? Or perhaps a way to save the instrumentation to be selected from the "Custom Ensemble" List?