Changing the default ATC call sign in FSX?

In the "Select Aircraft" menu, has any one figured out yet how to change the default ATC call sign in FSX, the same as it does in FS 2004, (Also select the Airline)...?
...or am I missing something...?
Changing the ATC call sign also placed your own registration letters/numbers on the fuselage of certain aircraft...
...!
Cheers all...!
Paul...
...!
..there seem to be a number of options missing in FSX compared to the previous versions...!
...or am I missing something...?
Changing the ATC call sign also placed your own registration letters/numbers on the fuselage of certain aircraft...

Cheers all...!
Paul...

..there seem to be a number of options missing in FSX compared to the previous versions...!