our $VERSION = sprintf("%d.%03d", '$Name:  $' =~ /(\d+)_(\d+)/,0,0);

##</code><code>##

WriteMakefile(
#    ...
    'VERSION_FROM'      => 'Module.pm' # filename to get version from
#    ...
);

##</code><code>##

> cvs tag v1_23-some-extra-info-that-gets-ignored

##</code><code>##

#!/bin/sh

BUILDDIR=/tmp
MODULE=my-distibution-name

if [ ! -n "$1" ]; then
    echo "Use 'release.sh TAGNAME' to make a release";
    exit 1;
fi

cd $BUILDDIR && rm -rf $MODULE &&
cvs export -r $1 $MODULE &&
cd $MODULE &&
perl Makefile.PL && make distcheck && make test && make dist && echo "All done"