ISAPI Rewrite of HTTPS Domains

Question

I'm pretty new to isapi rewrites on IIS. I need to get the following rule applied :-

I need https://www.xxx.co.nz to be redirected to https://www.xxx.com - including any additional paths and/or query strings.

I've tried this but it just loops:

#RewriteCond %HTTPS on
#RewriteCond Host: (?!^https://www.xxx.co.nz)(.+)
#RewriteRule /(.*) https\://www.xxx.com/$2 [I,RP]

Any ideas?