Best way to deploy feature branch releases to one server on different ports

In our development process we create releases of feature branches. Ideally, we’re thinking of deploying these branch releases to the same IIS server and run them on different port numbers. What would be the best way to achieve this? Ideally, somewhere in the process we have an incrementing variable that is used as a dynamically assigned port number. But it looks like this is not possible.

So it seems I’m left with creating a generic process step, with the port number as a variable and then create a discrete number of projects, one for each port number…? That doesn’t feel right either.

Any guidance on what the best approach to this would be is very welcome.

Thanks, Pascal