I don't have Windows, but after googling a bit, it looks like IO::Uncompress::Unzip and IO::Compress::Zip does what you want from a high level interface. That will save you the trouble of dealing with IO::Scalar manually unzipping and tracking position. There are examples in the docs.

Also see using IO::String instead of IO::Scalar for in memory zip files.

With IO::Scalar, the basic example is:

use IO::Scalar;
my $memory_file = '';   #scalar as a file , 
my $memfile_fh = IO::Scalar->new(\$memory_file); #filehandle to the sc
+alar

# write to the scalar $memory_file
my $status = $zip->writeToFileHandle($memfile_fh);
$memfile_fh->close;
[download]

Googling around I found this for Windows. Chilcat zip utility which claims to do in memory access in Windows.