how to change to another servlet root?

[shikida]

this is probably a stupid question, but I'd like to set Stapler to a directory not /

for example, from this site

http://stapler.kohsuke.org/getting-started.html

since I set the Stapler root to be

[servlet]
[servlet-name]Stapler[/servlet-name]
[servlet-class]org.kohsuke.stapler.Stapler[/servlet-class]
[/servlet]

[servlet-mapping]
[servlet-name]Stapler[/servlet-name]
[url-pattern]/[/url-pattern]
[/servlet-mapping]

this means that the URL

http://myserver:myport/

is mapped to the Stapler servlet. This is ok.

Now, I'd like to make it answer to

http://myserver:myport/somedir

obviously, just changing the configuration below is not enough

[servlet]
[servlet-name]Stapler[/servlet-name]
[servlet-class]org.kohsuke.stapler.Stapler[/servlet-class]
[/servlet]

[servlet-mapping]
[servlet-name]Stapler[/servlet-name]
[url-pattern]/somedir/[/url-pattern]
[/servlet-mapping]

how can I change Stapler in this case?

TIA

Leo