syntax error at line 2: `unshift' unexpected

I'm trying to archive a mailing list on the fly.

I created a user "list" on my solaris box and created list's .foward file:
 created a user "list" on my solaris box and created list's .foward file:

\list, "| /usr/local/bin/mhonarc -add -quiet -outdir -/export/home/list/archive"

when I send mail list, I get an error from mhonarc (bounce back mail):

/usr/local/bin/mhonarc: syntax error at line 2: `unshift' unexpected
554 "| /usr/local/bin/mhonarc -add -quiet -outdir 
-/export/home/list/archive"... 
unknown mailer error 2

I'm using a perl5 binary.  When I try with perl4 I don't get the unshift error, 
but it can't find newgetopt.pl


I'd GREATLY appreciate help on this.

Sam Brodkin