Thanks for your help, but I got it working a different way - using DBI.

For anyone who's interested - it seems difficult to find info on accessing MS SQL Server from Perl. I used DBI and DBD::ODBC - I was able to get a connection going with Win32::ODBC and RDBAL but wasn't sure about running stored procedures with these methods.

Here's the code...note you need to install DBI, DBD::ODBC and set up a system DNS to connect to database from your ODBC data sources control panel - there may be a way to get a DSN-less connection though. Also, you must initialise any parameter being bound to a placeholder and used as an output parameter to the stored procedure to some valid value of the expected datatype. If you're expecting a string then initalise to ' ' or other string value. If you're getting some datatype conversion error ("error converting data type ... to ..."), then this could be the problem.

use DBI;
use DBI qw(:sql_types);

my $MSSQL_uid = 'myuid';
my $MSSQL_pwd = 'mypwd';
my $MSSQL_svr = 'mysqlsvr';
my $MSSQL_db  = 'mydb';
my $MSSQL_dsn = "dbi:ODBC:$MSSQL_db";
my $sth; # statement handle

# connect to DB
my $dbh = DBI->connect($MSSQL_dsn, $MSSQL_uid, $MSSQL_pwd)
   or die "Couldn't connect to $MSSQL_svr : $DBI::errstr\n";
print "\n\nConnected to $MSSQL_dsn DS\n\n";

# execute stored procedures and get output parameter value
my $param1_int = 0; # note you must initalise this to something 
my $exe_string = "EXECUTE my_stored_procedure" .
                 "?, " .
                 "'$param2_str', " .
                 "'$param3_str', " .
                 "$param4_int";
$sth = $dbh->prepare($exe_string) 
    or die "\nCouldn't prepare statement : $DBI::errstr\n";
$sth->bind_param_inout(1, \$param1_int, 50) 
    or die "\nCouldn't bind param inout : $DBI::errstr\n";
$sth->execute
    or die "\nCouldn't execute stored procedure : $DBI::errstr\n";
print "Output parameter value is now $param1_int\n";

# disconnect from DB
$dbh->disconnect
   or die "\nError disconnecting : $DBI::errstr\n";
[download]

Andrew