Well, yes, in one way (this should solve the technical problem), and in another, emphatic no. Never pass user input directly to a subshell -- all sorts of nasties could result. Suppose $string is "foo *; cat /etc/passwd; rm -rf " for example. DoS, cracker info, and evil file removal (potential) all in one go.
So you could use this sort of thing, but *not* without taint checking, and, if you're going to untaint, be sure you know what you're doing. For more, see perldoc perlsec on your system, or perlsec hereabouts.
perl -e 'print "How sweet does a rose smell? "; chomp ($n = <STDIN>);
+$rose = "smells sweet to degree $n"; *other_name = *rose; print "$oth
+er_name\n"'