driver (program) intermediary between the Windows system and the RS232 printer

Question

Drivers

Greetings!
There is a task of filtering / logging / replacing text when printing from under Windows.
The printer hangs on the COM port.
I see the following structure. The driver or program creates a virtual COM port, which is seen by Windows as a printer, and itself clings to a physical printer. All input / output between the physical and virtual ports filters through itself.
The question is next. What should it be? Program or driver? Haven't written drivers yet. Correct/suggest a different structure.
If it's still a driver, then what development package do you think it's faster to implement? (I myself wrote in C, PERL).
Thank you in advance.

Answer 1

By itself, a com port cannot be a "printer" port. RS-232 does not have a sufficient level of self-awareness.
You can create a pair of virtual com ports, for example, using com2com .
Then you can connect the logical port of the printer with one port from the com2com pair, hang up an intermediary program between the second port of the virtual pair and the physical port of the printer.
In my opinion, it should work, problems are possible only if a certain timing is required when communicating with the printer.

Answer 2

Google on request "windows rs232 filter" finds realterm.sourceforge.net/
Judging by the description, it can both intercept data and send its own.