UDR with esqlc ?

Hello there, I wonder wether I could register an esqlc function as an UDR in my database. I tried to build a shared object libary with my function in it with a 'cc -G function.o -o lib.so' - line. And I tried to register it in the database. There where no error message but I could not execute it. So I tried to run it within a C - program that links the lib.so , but the '.so' file could not be accessed. What was wrong ? (I'm using IDS 9.14 on sun solaris.) Thanks Ilona