Simple Sitemaps for Multisite rewrite rules on IIS server

Hi,

I would like to install sitemap.php into my wp-content folder, but when it comes to the rewrite rules, I'm in a bit of a bind as I'm using an IIS server. This means that I don't have a .htaccess file, but rather a web.config file.

Currently, this is what that the web.config file looks like:

<?xml version="1.0" encoding="UTF-8"?>
<configuration>
    <system.webServer>
        <rewrite>
            <rules>
                <rule name="WordPress Rule 1" stopProcessing="true">
                    <match url="^index\.php$" ignoreCase="false" />
                    <action type="None" />
                </rule>
                <rule name="WordPress Rule 2" stopProcessing="true">
                    <match url="^([_0-9a-zA-Z-]+/)?files/(.+)" ignoreCase="false" />
                    <action type="Rewrite" url="wp-includes/ms-files.php?file={R:2}" appendQueryString="false" />
                </rule>
                <rule name="WordPress Rule 3" stopProcessing="true">
                    <match url="^([_0-9a-zA-Z-]+/)?wp-admin$" ignoreCase="false" />
                    <action type="Redirect" url="{R:1}wp-admin/" redirectType="Permanent" />
                </rule>
                <rule name="WordPress Rule 4" stopProcessing="true">
                    <match url="^" ignoreCase="false" />
                    <conditions logicalGrouping="MatchAny">
                        <add input="{REQUEST_FILENAME}" matchType="IsFile" ignoreCase="false" />
                        <add input="{REQUEST_FILENAME}" matchType="IsDirectory" ignoreCase="false" />
                    </conditions>
                    <action type="None" />
                </rule>
                <rule name="WordPress Rule 5" stopProcessing="true">
                    <match url="(^[_0-9a-zA-Z-]+/)?(wp-(content|admin|includes).*)" ignoreCase="false" />
                    <action type="Rewrite" url="{R:2}" />
                </rule>
                <rule name="WordPress Rule 6" stopProcessing="true">
                    <match url="^([_0-9a-zA-Z-]+/)?(.*\.php)$" ignoreCase="false" />
                    <action type="Rewrite" url="{R:2}" />
                </rule>
                <rule name="WordPress Rule 7" stopProcessing="true">
                    <match url="." ignoreCase="false" />
                    <action type="Rewrite" url="index.php" />
                </rule>
            </rules>
        </rewrite>
        <handlers accessPolicy="Read, Execute, Script" />
        <httpProtocol>
            <customHeaders>
                <add name="X-UA-Compatible" value="IE=edge" />
            </customHeaders>
        </httpProtocol>
    </system.webServer>
</configuration>

Where and how do I add the following line? I'm not sure how to change the code to fit with a web.config file.

RewriteRule ^(.*/)?sitemap.xml wp-content/sitemap.php [L]

Much thanks!