From the HELP text in vB:
DefaultTrayID Property
Returns or sets the default tray your printer uses to print
documents.
Read/write WdPaperTray.
WdPaperTray can be one of these WdPaperTray constants.
wdPrinterAutomaticSheetFeed
wdPrinterDefaultBin
wdPrinterEnvelopeFeed
wdPrinterFormSource
wdPrinterLargeCapacityBin
wdPrinterLargeFormatBin
wdPrinterLowerBin
wdPrinterManualEnvelopeFeed
wdPrinterManualFeed
wdPrinterMiddleBin
wdPrinterOnlyBin
wdPrinterPaperCassette
wdPrinterSmallFormalBin
wdPrinterTractorFeed
wdPrinterUpperBin
Remarks
You can use the DefaultTray property with a string from the
Default tray box on the Print tab in the Options dialog box
to set this same option.
Example
This example sets Word to use the upper print tray, and
then it prints the active document.
Options.DefaultTrayID = wdPrinterUpperBin
ActiveDocument.PrintOut
This example returns the current setting of the Default
tray option on the Print tab in the Options dialog box.
Dim lngTray As Long
lngTray = Options.DefaultTrayID