problem with physical serial port COM1

[Fabripcn]

Hi everyone,
we have this problem with serial ports:

We have a device connected to the PC (Windows XP) via serial port. Unfortunately the PC is old and we need to replace it but the software only works on Windows XP.
We have virtualized Windows XP with Virtualbox 7.0 on a new machine (which has the physical serial port) and installed the software but we have problems with the serial port. If we enable it with Port number COM1 - Host Device COM1, however the computer is unable to communicate with the device that is physically connected to the serial port. Are there any other settings I should look at?
Thanks everyone for the help.

[AndyCot]

Is the app a DOS app or Windows app?

[jorgensen]

Try this: viewtopic.php?t=26860