Collecting information from other topics and using some imagination and experimenting a bit I ended up in finding out the arguments of the call patterns you need to insert in order to make Thunderbird work similarly to outlook in click.to. So when you add a new "windows application call" and you are requested to customize the new application, you need to enter the app name, the path in your hard disk and the following to the "Arguments of the call" field:
in case you want the copied test appear in Thunderbird's new mail Body
in case you want the copied test appear in Thunderbird's new mail Subject
I have tried both of the above with click.to version 0.9.7.1370 and works fine!