VBA: print .prn files to a network printer using LPR

I have this Word VBA code that merges a number of documents into .PRN files.

Next I want to send these .PRN files to a network printer using the lpr command.

At this moment I try to do this with the following piece of code:

‘ Send PRN files to Emtex
Call Shell(“lpr -S 10.x.x.x -P dl-pcl” & strPath & “*.prn”)

when debugging the code the step is passed without errors but no files appear in the printerqueue.

Does anyone have an idea how to do this?

Thanks in @vance
Jaap