Hi Timo...
I tried POINST when I first started with Pelles and never did get it to work the way I would like... not that it doesn't work, more that I needed something different. I've been using
Inno Setup which I find is more flexible and a lot easier to script.
I haven't been able to open and look at any of POINST's .exe files with any archive viewer, so I don't know what protocols it uses...
Sorry I can't be more help. I think we need Pelle for this one...