In almost all cases it is pretty straight forward:
Install both applications
Install 2 printer queues.
Activate the ELP software in the first queue, where the data comes in.
Generate your ELP ini file processes, but also add to section GLOBAL:
; In this case the section is always triggered, because of the printer name.
; do not print anything or set the queue to port "nul"
; but send the out stream to the second queue with the second Print Processor.
; if #HOSTNAME# does not work use local host instead: 127.0.0.1
A little more complex is it, if ELP needs to do some stuff behind the "second" queue. In this case the term of first and second is exchanged. Here is what needs to be done: Sharing print queues using TCP/IP services (LPR protocol)
Tip: Set both queues to hold, print and see how the data is processed from one queue to the other.
Note: The owner of the data stream (User name) could be lost on the way from queue 1 to queue 2. In that case
make sure that the name is passed in the PJL section of the data stream.
or you may try to use the "Process User" option with the "Current" or a "Named" user account, but this might not always work out.