Let me cut & paste some code I have:
First, lets say you have a printer who's IP address is {string}:
"192.168.33.99"

And then, lets say you have a Queue on your printer, like:

"XRX_Swop"

Then this is the code I would use:

VB Code:
  1. 'In a sub somewhere:

  2.  
  3. MyLPStr = "lpr -S " & "192.168.33.99" & " -P " & "XRX_Swop" & " "

  4. SyncShellCmd MyLPStr & "-J" & Chr$(34) & "p003456-save" & Chr$(34) & " " & Chr$(34) & "C:\p003456-duplex-save.pdf" & Chr$(34), 0

  5.  
  6.  
  7. 'Then, you have the function SyncShellCmd somewhere in your

  8. 'forms code:

  9.  
  10. Public Function SyncShellCmd(CmdStr As String, ByVal ApplicationFocus As Long) As Boolean

  11. 'Run the application by the CmdStr, and exit when the program terminated, Application focus specific

  12. 'the focus of the application. e.g vbNormalFocus

  13. Dim lPid As Long 'The task ID of the started program

  14. Dim lHnd As Long ' handle to object to wait for

  15. Dim lRet As Long 'Return value of WaitForSingleObject()

  16.  
  17. SyncShellCmd = False

  18. If CmdStr = "" Then Exit Function

  19. lPid = Shell(CmdStr, ApplicationFocus)

  20.     If lPid <> 0 Then

  21.     'Get a handle to the shelled process.

  22.     lHnd = OpenProcess(&H100000, 0, lPid)

  23.     'If successful, wait for the application to end and close the handle.

  24.         If lHnd <> 0 Then

  25.             lRet = WaitForSingleObject(lHnd, &HFFFF) 'no time out

  26.             CloseHandle (lHnd)

  27.             SyncShellCmd = True

  28.         End If

  29.         

  30.     End If

  31.  
  32. End Function

  33. 'Either put these three in a Bas, declared as public,

  34. 'or at the top of your forms code module:

  35.  
  36. Private Declare Function OpenProcess Lib "Kernel32.dll" (ByVal dwDesiredAccessas As Long, ByVal bInheritHandle As Long, ByVal dwProcId As Long) As Long

  37. Private Declare Function WaitForSingleObject Lib "kernel32" (ByVal hHandle As Long, ByVal dwMilliseconds As Long) As Long

  38. Private Declare Function CloseHandle Lib "kernel32" (ByVal hObject As Long) As Long

-Hope this helps
-Lou

BTW, the point of all this is you are essentially shelling to the LPR.exe, if you happen to have it on your system.