inspired by a comment by LarryLeonard i have just added the following templates for C/C++ to VAX:
#if:
#if 0 //{{AFX_COMMENTED_OUT-?
#en:
#endif //}}AFX_COMMENTED_OUT-?
add in setting the "Wizard code" to a similar green colour to normal comments, and now all of the code in my #if 0, #endif blocks is coloured in as comments
so for the other people out there who also wanted this, this is how you do it :) admittedly you need to do slightly more editing when toggling between #if 0 and #if 1, but it is a good start