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exec("lp -d T100__STR_T_U001_ $FilePathOfFileReadyToPrint", $PrintResult)
I've looked at the print library for windows but thought I would ask before I go down that path.
Second - windows printing can be a real pain, however if you have a postscript compatible printer and can get your output into postscript then there are plenty of methods (including free 3rd party command line apps) to send that postscript directly there.
I'm open to any ideas.