How can I get around this issue?
The only way to get around this issue is to install Windows XP in a virtualized environment (eg. Virtualbox or VMWare). According to previous experience, this software doesn't even have compatibility with Windows 10.
You can download VirtualBox from the following link: http://virtualbox.org and use the tutorial to create a machine where you can install Windows XP to run Procomm Plus: https://www.virtualbox.org/manual/ch01.html#gui-createvm
You can easily install old 32-bit application when starting Windows 10 with disabled driver signature enforcement.