Progress - How to concatenate many rows with same id in sql?

Question

My table contains those values :

NODOS PROCEDURE PHASE
  1     CXP      PRB
  1     CXP      PEX

And I want this :

NODOS PROCEDURE PHASE
  1     CXP      PRB, PEX

I use the progress database. Everything I've tried doesn't work (String_AGG, Group_concat...) because it's a special database. Does anyone have any ideas?

Regards,