Regex filter in icedove

[Gary Roach <gary719_list1@verizon.net>]

Hi all;

I am plagued with junk mail with non-asci characters in the subject 
line. There is a "Subject Regex Match" filter in the message filter 
applicateion in icedove. I would like to filter out all messages with 
non-ascii characteristics in the subject. I have tried [\x126-\x255], 
[^[\x00-\x75]], [\x76-\xFF] and [^[:ascii:]]. None work. I can't find 
documentation for this function. Since there are several different 
flavors of regex I really don't know what I am doing. Can anyone help.

Gary R.