One option is to use one of the XML::* modules and just write an XML document to store your data.

Another option, which is probably the easiest, is to use Data::Dumper, and print the structure to a file. Then when you read it back in, just store it in a var and eval it. Just be careful, since you are evalling, to check the content for system, exec, backticks, etc., to make sure it hasn't been tampered with.

Update:
I checked ActiveState for Config::General, and the reason you can't get it for Win32, is because it failed compilation. Take a look here for a list of Config::* modules that have compiled on Win32.