Thanks for posting your question in the Microsoft Q&A forum.
Here's a revised version of your rule that should capture all URLs under the /cmsvd
folder and redirect them to the new server:
<rewrite>
<rules>
<rule name="RedirectToNewServer" stopProcessing="true">
<match url="^cmsvd/(.*)" />
<conditions>
<add input="{HTTP_HOST}" pattern="^servername\.com$" />
</conditions>
<action type="Redirect" url="https://newservername.com/CMSVD/{R:1}" />
</rule>
</rules>
</rewrite>
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