While parking is easy (routing the call to park/any will automatically create a parking orbit and transfer the call) picking it up is a bit more complicated and requires scripting.
We'll use the pickup.php included in yate's svn.
See Using Yate's PHP library on windows for instructions if you are using windows.
Add the following to extmodule.conf:
or add a listener and then execute "php pickup.php" if you are running yate on windows.
[listener test] type=tcp addr=0.0.0.0 port=5039 role=global
after restarting yate dialing #82000 will pickup parked calls in FIFO order.
No configuration file.