[pmwiki-users] Attach:image question

[Hans]

Attach:example.jpg renders <img> tag HTML with a full url http://....
to the uploaded image.

Is there a way to shorten this to a relative file path, like
 <img src="images/example.jpg" ... />

having set

$UploadDir = 'images';
$UploadPrefixFmt = '/';

in a certain local/Groupname.php file for the wiki group Groupname.

If necessary, I could also use Img:example.jpg,
setting  $IMap['Img:'] = '$1'; or something like that.

so I like a relative file path in img tags, but I like to retain
an upload link for images not yet uploaded.
Is that possible?

Thanks!
  ~Hans