How do I write a rule for the subject header, but for working on the=20=

mimedecoded contents?

For instance a simple rule to check the length of the subject:

header BW_SUBJECT_LONG Subject =3D~ /.{100}/

Problem is - when the subject has been mime-encoded, it's already very
long:=20

Subject:
=3D?iso-8859-1?q?Danmarks_st=3Df8rste_smartphone-projekt_snart_i_luften=
_=3D2f_Unders=3Df8gelse:_Lille_?=3D=3D?iso-8859-1?q?gevinst_ved_offshor=
ing_=3D2f_Software_som_service_er_endelig_p=3De5_v ej?=3D


/Per Jessen, Z=C3=BCrich