Yes, you can.
See docs http://docs.flashphoner.com/display/WCS/Click2call+quick+start
accounts.xml and callee.xml are just examples.
If you create your own click to call service, you will need to use dynamic php(or other) scripts.
For example:
http:/mydomain.com/account.php?token=123 -returns SIP account login and password as XML for user with token 123
http:/mydomain.com/account.php?token=124 -returns SIP account login and password as XML for user with token 124
…
etc
And the same for callee.xml, you need dynamic script
callee.php?token=123 returns number +79220000000
callee.php?token=124 returns number +79220000001
etc
So, you are able to serve unlimited accounts, tokens and call directions.
