I think this might be your problem:

$cmd[0] = "copy $workarea\\$sec_homepage\\data\\$key $archive\\$sec_ho
+mepage\\data\\$key";       
$cmd[1] = "del /Q $workarea\\$sec_homepage\\data\\$key";
$cmd[2] = "$cmd_path\\iwsubmit -w -u $vpath/$submit/data/$key \"Conten
+t Expired.\"";
$cmd[3] = "$cmd_path\\iwsubmit -w -u $vpath_arc/$submit/data/$key \"Su
+bmitted to Staging.\"";
[download]

None of those variables are passed to the sub, or created in the sub. Therefore, they are unitialized. I think what you mean to do is store those names in the @cmd array. To do that, the $ need to be backslashed.

$cmd[0] = "copy \$workarea\\\$sec_homepage\\data\\$key $archive\\\$sec
+_homepage\\data\\$key";       
$cmd[1] = "del /Q\$workarea\\\$sec_homepage\\data\\$key";
$cmd[2] = "\$cmd_path\\iwsubmit -w -u \$vpath/\$submit/data/$key \"Con
+tent Expired.\"";
$cmd[3] = "\$cmd_path\\iwsubmit -w -u \$vpath_arc/\$submit/data/$key \
+"Submitted to Staging.\"";
[download]

If that isn't it, please tell us what your function is supposed to do :)