Admin Subtheme for node editing

I have set up virtual sites which use pathauto to determine the condition which activates the site. So the condition is 'only on the listed pages x*, y*'.

This means that the virtual site theme is not used for editing because the path is not aliased - it is just node%/add or node/%/edit. Can someone help me with some php code to set a condition that means that the node/%/add and node/%/edit paths also activate the virtual site and therefore the correct theme? I'm guessing that it must need to somehow match drupal_get_path_alias(nid) to the x* and y* but I'm not sure how to do that.