"eval" variable in non-perl statment?

ftforger has asked for the wisdom of the Perl Monks concerning the following question:

I have a script something like this (I know this doesn't work, this is just a rough sample)

$v1="user_value1";

open(INFILE,"<template.file");
$input=<INFILE>;
eval $input;
$line = "$input";
close(INFILE);

print "$line\n";
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with the contents of "template.file" being

thing1 type1 $v1
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What I want is when the script runs, the print would produce:

thing1 type1 user_value1
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