I have a feature which needs to install a msi-package of 200 megabytes. I dont want to download the entire file if not necessary and i dont want to import the file, since this will mess up the rest of my installation.
Absolutely. Use scripting - the Download File plug-in command will download any file over HTTP/FTP, or even a local network. Then run it using the (Un)Install MSI Setup plug-in command.