You could to this with a little eval magic (see the caveats, later). What I have in mind would be something like the following:

  if( $sampleData =~ /$searchString/ ) {
      print eval qq{"$outputString"};
  }
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The outer qq{} quote is used to generate an evaluateable string by adding double quotes around the original. When evaluated, this new string interpolates your variables into place.

There are a few problems with this approach:

• You may need to escape characters in the string (: at a minimum)
• This is effectively compiled at run-time, which means unexpected errors can result.
• You need to carefully scrub the output strings to prevent injection attacks.

You are basically trusting the incoming string to be safe to evaluate and run as code. This is not always a valid or safe assumption.