REM run the script that sets environment variable FOO 
call foo.bat
REM now %FOO% is set in the environment

REM Corion;s suggestion: if you need the entire environment
REM set called by itself dumps one line each VAR=VALUE
set

##</code><code>##

REM run the script that sets environment variable FOO 
call foo.bat
REM now %FOO% is set in the environment

REM my suggestion: send just a few to stdout
echo FOO=%FOO%
echo BAR=%BAR%

##</code><code>##

use strict;
use warnings;

#backticks convert anything sent to stdout into a string
#so this should fill $sEnvironment with assignments
my $sEnvironment=`wrapper.bat`

#now parse $sOutput and store the various VAR=VAL pairs
my @aAssignment=split(/[\r\n]+/,$sEnvironment);
foreach my $sAssignment (@aAssignment) {
  $sAssignment =~ /^(\w+)=(.*)$/;
  $ENV{$1}=$2;
}