[exim] exiscan questions

Hi,
I've read the spec and Googled, but can't find an answer these questions:

1) How to specify case insensitivity across all expressions?

Here is a simple example from the spec:

deny message = contains blacklisted regex ($regex_match_string)
      regex = [Mm]ortgage : URGENT BUSINESS PROPOSAL

2) Can I use MACRO in this simple example, e.g.

deny message = contains blacklisted regex ($regex_match_string)
      regex = {PROFANITY}

3) Can I use the \N?

Thanks
Craig