Thank you all for the suggestions.
My problem is solved !
I made a combination of the answers and suggestions of this forum and the german yamaha forum .
I tried it and it was successful.
Here are the solutions :
When you are “playing” a midifile on your keyboard ,there are two possibilities to receive the midi signals in your sequence program [ like cubase sx] on your pc .
1. connect the midi out cable to the “midi out B” [ at the back side of the 9000 pro ] . normally the cable is connected to the “midi out A “when you are playing .
now the sequencer will receive the midi signals in a normal way .
or
2. click on “file” in cubase sx and then at “import” , and then “midi file “.
Now the sequencer also receives the midi signals from your 9000 pro .

Easy when you know it , but that’s like life : experience of others will help you to survive !
Guillermo