to test the non-existence of a dir

Hi,

Xymon allow me to test the non existence of file or directory. But I'd 
like a more complex test. In my case, I don't want any directory named 
_FIXED_PART_anything in a whole tree.
Example :

I've
/toto/_FIXED_PART_1 -> test is red
/toto/a/sub/directory/_FIXED_PART_hello_world -> test is red

So, is there a "normal" way to use "files"  test included in xymon ?

Regards,
Damien