I want rewrite $tU but I&#39;m not being able, I&#39;m doing the following:<div><br></div><div><div>   remove_hf(&quot;To&quot;);</div><div>  insert_hf(&quot;To: sip:$rU@$rd\r\n&quot;, &quot;From&quot;);</div></div><div><br>
</div>