Redirect to subdomain using web.config rules - asp.net

Question

we migrate our webapp hosted in a directory "webapp" inside main domain:
http://www.example.com/webapp/
To the new subdomain without "webapp" folder:
http://subdomain.example.com/
I need to redirect only subdir "webapp". I don't want to redirect other url like http://www.example.com/, http://www.example.com/folder1, http://www.example.com/folder2, ....
But we have already sent a lot of emails to customers with link inside like: LOGIN TO YOUR DASHBOARD or other link like DOWNLOAD YOUR DOC
Now i'm trying to do a redirect trough web.config but it seem that nothing work.
If I try no navigate to, for example, http://www.example.com/webapp/login i don't get redirected to http://subdomain.example.com/login/ as expected.
If I try no navigate to, for example, http://www.example.com/webapp/data/download.php/id=43 i don't get redirected to http://subdomain.example.com/data/download.php/id=43 as expected.
Any suggest?
<rule name="redirect-to-subdomain" stopProcessing="true">
<match url="^webapp/$" />
<conditions>
<add input="{REQUEST_FILENAME}" matchType="IsFile" negate="true" />
<add input="{REQUEST_FILENAME}" matchType="IsDirectory" negate="true" />
</conditions>
<action type="Redirect" url="http://subdomain.example.com/{R:0}" redirectType="Permanent" />
</rule>

Answer 1

You rule won't work except for http://www.example.com/webapp/.
If you want to redirect link like http://www.example.com/webapp/login. Please try this rule.
<rule name="redirect-to-subdomain" stopProcessing="true">
<match url="^webapp/(.*)$" />
<conditions>
<add input="{REQUEST_FILENAME}" matchType="IsFile" negate="true" />
<add input="{REQUEST_FILENAME}" matchType="IsDirectory" negate="true" />
</conditions>
<action type="Redirect" url="http://subdomain.example.com/{R:1}" redirectType="Temporary" />
</rule>