You can hook up one of the standard Windows API calls ShellExecute

 Function long ShellExecute( long hwnd,  string lpOperation, string lpFile, string                  
          lpParameters,  string lpDirectory,  integer nShowCmd ) Library "shell32.dll"   
          alias for "ShellExecuteW"

Once you have done this, you can send your path/file to this function and tell it to print, like so:

 integer        li_return_code
 string     ls_null
 long       ll_null

 SetNull(ls_null)
 SetNull(ll_null)

 li_return_code = ShellExecute(ll_null, "print", "C:\File.pdf", ls_null, ls_null, 0)

 ที่มา : http://stackoverflow.com/questions/7669649/print-files-from-a-folder-in-powerbuilder-12