IIS URL Rewrite to not pass the .htm into the rewrite - iis

Question

I have an IIS server with many domains multihomed. I have base rewrite rules for seo friendly URLS.
Example:
www.something.com/here-is-the-page
current converts to
www.something.com/index.htm?pagetitle=here-is-the-page
Problem is that one domain needs this rule to allow the URLs to read with .htm on the end.
Example:
www.something.com/here-is-the-page.htm
needs to convert to
www.something.com/index.htm?pagetitle=here-is-the-page
(note, just removed the .htm, although I still want the .htm to display in the location bar)...

Answer 1

Thanks everyone for all of the assistance...[sarcasm] below is the solution.
The key here is the MatchAll.
Look at the URL
Check to see if this is for www.something.com
Check to make sure there is not an actual file with the filename.htm
Check there is no directory with that name
If the file is sitemap.htm (which does exist, then do not process) This should be caught by the previous check for file, but just got added for overkill. Since this is a rewrite and not a redirect the .htm will remain displaying in the navigation bar.
<rule name="remove the htm" stopProcessing="true">
<match url="([_0-9a-z-]+)\.htm$" />
<conditions logicalGrouping="MatchAll" trackAllCaptures="false">
<add input="{HTTP_HOST}" pattern="^(www.something.com)$" />
<add input="{REQUEST_FILENAME}" matchType="IsFile" negate="true" />
<add input="{REQUEST_FILENAME}" matchType="IsDirectory" negate="true" />
<add input="{REQUEST_FILENAME}" pattern="sitemap\.htm$" negate="true" />
</conditions>
<action type="Rewrite" url="/index.cfm?pagetitle={R:1}" />
</rule>