Assigning PF_Source to a Particle Skinner

Hello,

This is my first foray into maxscript, and I have nearly achieved what I'm after. If only I could do this one simple thing! Any help would be much appreciated.

I've written a short script that creates a particle system and a rectangular poly. I then want to bind the newly created PF_Source to the newly created poly with a Particle Skinner. The end result will be a script that emits sheets of paper every n frames that will then swirl around my scene.

Here is the portion of script for creating the rectangular poly and it all works, except the bit that tries to attach/define the Particle_Flow_Systems

	Rectangle length:280 width:210 cornerRadius:0 pos:position isSelected:on 
		$.name = "Paper" + (progressString)
	modPanel.addModToSelection (Garment_Maker ()) ui:on
		$.modifiers[#Garment_Maker].density = 0.02
	macros.run "Modifier Stack" "Convert_to_Poly"
	modPanel.addModToSelection (Particle_Skinner ()) ui:on
		$.modifiers[#Particle_Skinner].Particle_Flow_Systems = #("pFlow" + (progressString))
		$.modifiers[#Particle_Skinner].activateSkinning()
	modPanel.addModToSelection (TurboSmooth ()) ui:on
	modPanel.addModToSelection (UVWMap ()) ui:on
		$.modifiers[#UVW_Map].realWorldMapSize = off

Like I say, this is my first go at maxscript so I'm still learning how the syntax works etc which will hopefully explain any howling errors.

Thanks in advance,

James