The Internet Information Services 7 (IIS 7) URL Rewrite Module in Windows Server 2008 provides an import feature that truly simplifies the process of converting Apache mod_rewrite rules to IIS URL rewrite rules. You simply use the Import Rules feature provided in the URL Rewrite Module to import several mod_rewrite rules into an IIS configuration file. If you have not yet downloaded the URL Rewrite Module, you can do so at http://www.iis.net/download/urlrewrite.
While setting up a Dolphin 7.0 site (from http://www.boonex.com) I needed to add URL rewrite rules to allow for user friendly permalinks. The rules were already written for Apache in an .htaccess file. I found the solution at http://learn.iis.net/page.aspx/470/importing-apache-modrewrite-rules/. The steps are easy to follow if you have access to the IIS manager (or an IIS 7 manager on a local server):
To convert these rules to IIS URL rewrite–specific format:
1. Start IIS Manager.
2. On the left, in the Connections pane, select the appropriate web site.
3. On the right, in Features View, click URL Rewrite.
4. On the right, in the Actions pane, click Import Rules.
5. Choose the .htaccess file to import, click Import.
6. Browse through the rules to ensure they are acceptable and click Apply. The imported rules are saved to the web.config file for the web site you chose.
IMPORTANT DISCLAIMER - The URL Rewrite Module tries to convert Apache mod_rewrite rules to functionally equivalent IIS URL rewrite rules. However, not all mod_rewrite rules can be converted because of architectural differences between Apache and IIS. It is highly recommended that you study a mod_rewrite rule set until you understand its functionality before you begin the conversion process. Then, after converting to IIS URL rewrite rules, review and test the result of the conversion to make sure that the corresponding IIS rewrite rule set provides the same URL rewriting logic.
Note that only rules that follow Apache mod_rewrite syntax can be converted. Any other formats of rewrite rules (for example, ISAPI_Rewrite, Ionic ISAPI Rewrite, IISRewrite, and others) are not recognized or will be converted incorrectly.