multiple wordlists from the command line?

[Chris Fortune]

>   bogofilter --wordlist=R,user,~/wordlist.db,1 --wordlist=R,system,/var/spool/bogofilter/wordlist.db,1

thanks David.  it works well on the command line, but when executed from a perl script I get this error message:

     $res2 = `/usr/local/bin/bogofilter -T -x
c --wordlist=R,system,/home/defaultuser/.bogofilter/wordlist.db,1 --wordlist=R,user,/home/defaultuser/.bogofilter/$uid/wordlist.db,1
< $temp_file 2>&1`;
    print $res2;
    "Can't find HOME or BOGOFILTER_DIR in environment."

any ideas?