Pleading help from someone who is into Vbscript and Adobe Illustrator with regards to using script to access a custom preset in Illustrator. What I am trying do is a take an Tiff image and trace it with a custom trace I have created.

I've created a few VBscripts with Illustrator successfully but this has stumped me after weeks of testing. Apparently, it can be done. I have API documentation, Java and VBA examples but this is over my head.
Any takers?

Here is what I have so far (one of many renditions):

Code:
Set App = CreateObject("Illustrator.Application")
Set FSO = CreateObject("Scripting.FileSystemObject")
Set SourceFolder = FSO.GetFolder("S:\SOCAL\Section_31\Land Cover")


Dim FileRef
For Each FileRef In SourceFolder.Files
	
	Set AutoCADOpenOptions = App.Preferences.AutoCADFileOptions
		AutoCADOpenOptions.MergeLayers = false
		CurrentInteractionLevel = App.UserInteractionLevel
		App.UserInteractionLevel = -1 ' aiDontDisplayAlerts
		Set myDoc = App.Open(FileRef.Path,2)
		App.UserInteractionLevel = CurrentInteractionLevel
		
		ubound(App.TracingPresetsList)
		' The line below loads tiff file into Illustrator ready for a custom trace
		App.DoScript "LandCover-1", "Land Cover Auto"
		
		' From thi point on I am having no success. Need help building this out.
		Dim idoc    : idoc    = App.ActiveLayer
		Dim iplaced : iplaced = App.PlacedItem
		Dim itraced : itraced = App.ActiveLayer
		Dim iFile   : iFile   = FileRef.PlacedItems.Trace
		
		iFile.tracing.tracingOptions.loadFromPreset(tracingPresets[3])
		
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