In addition:

If you want to treat the value of $hashnew{$com} as a string literal (avoid regexp semantics), use the \Q...\E construct:

if (/\Q$hashnew{$com}\E/) {
# ...
[download]

This is highly recommended if $hashnew{$com} comes from untrusted sources (because otherwise it can open a security hole). It also helps avoid weird behaviour or sudden death (in case $hashnew{$com} happens to contains regexp control characters).

If you want to avoid the regexp overhead, you can use index:

if (index($_, $hashnew{$com}) + 1) {
# ...
[download]

All of the above applies only if you want $hashnew{$com} to behave as a simple substring, not as a sub-regexp. (your post is vague, so I'm guessing)