If the only thing you want to do is redirect the user after form submission, just set the #redirect property of the form.<br><br>$form[&#39;#redirect&#39;] = &#39;my/custom/path&#39;;<br><br>Alternatively, you could call your form with a parameter:
<br><br><a href="http://example.com/my/form?destination=my/custom/path">http://example.com/my/form?destination=my/custom/path</a><br><br>If you want to do some more advanced processing, I would put the additional information you want to add in a form element of type &#39;value&#39;, and it will be available in the form validation and submit handlers without ever appearing to the user.
<br><br>$form[&#39;my_custom_path&#39;] = &#39;my/custom/path&#39;;  <br>