Possibly try using the quotemeta function which backslashes all non-"word" characters. This might work for you: 
my $set_password = qq(/usr/bin/ssh $targethost "echo ')
                 . quotemeta($new_password)
                 . qq(' | /usr/bin/passwd --stdin $username");
system($set_password);

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In reply to Re^3: passwords with special characters are trying to kill me... no seriously! by johna
in thread passwords with special characters are trying to kill me... no seriously! by calmthestorm

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