Super Regex, interpolate variables in regular expressions with unicode

sRegExpWithUnicode.js

// Super RegExp
// @param regex A regular expression as literal or as string
// @param obj And object containing the values to replace inside the regex
// Usage: var regex = sRegExp( /Hello #{a}/, { a: 'World' } )
function sRegExp( regex, obj ) {
  regex = regex.toString();
  var newRegex = regex.replace(/(^\/|\/$|\/([igm]+)$)/g, '')
    .replace( /#\{(\w+)\}/g, function( a,b ) { return obj[b]; });
  var mods = regex.match( /\/([igm]+)$/ );
  return new RegExp( newRegex, mods ? mods[1] : '' );
}

// Convert a string or character to unicode
function toUnicode( str ) {
  return str.replace(/./g, function ( char ) {
    return '\\x'+ char.charCodeAt(0).toString(16).toUpperCase();
  });
}

// Example:
var pattern = sRegExp( 
  '/\\b[a-z#{a}-#{b}]+\\b/gi', 
  { a: toUnicode('À'), b: toUnicode('ÿ') } 
);

console.log( 'Hello año foobar sábado'.match( pattern ) );