La cadena original es:<b>123 4567 890abc def hijk lmnñopqrstuvwxyzABCDEFGHIJKLMNÑOPQRSTUVWXYZ!·$%&()=?żáéíÇç{}</b><br />Sustituiremos: <b>\w{3,6}</b> por: <b><span style='color:red;background-color:yellow'>A</span></b><br>El resultado será: <b><span style='color:red;background-color:yellow'>A</span> <span style='color:red;background-color:yellow'>A</span> <span style='color:red;background-color:yellow'>A</span> <span style='color:red;background-color:yellow'>A</span> <span style='color:red;background-color:yellow'>A</span> <span style='color:red;background-color:yellow'>A</span>ñ<span style='color:red;background-color:yellow'>A</span><span style='color:red;background-color:yellow'>A</span><span style='color:red;background-color:yellow'>A</span><span style='color:red;background-color:yellow'>A</span>MNÑ<span style='color:red;background-color:yellow'>A</span><span style='color:red;background-color:yellow'>A</span>!·$%&()=?żáéíÇç{}</b>