Truck open?

Dear technician,

A question, not about a malfunction but it’s more a desire...
In all my USA-cars (9? Since 1982) I could open the trunk from behind the steering wheel, just by pressing a button.
The Buick Century ‘99 I now have is the first one without such a button.
Can only open the trunk with the remote or with the key.
You’ll feel it coming:
Please let me know if, and where in the diagram I can find the right wires/connections so I can mount a small button in the dash, and by pushing it: a miracle, the trunk opens!
I also want to keep using the remote.

Would really be nice if you can help me with this one.
If not, no is also an answer.

Kind regards from the land of tulips and windmills,
Adrian B.