Informix-CLI connection to SE

I'm using Informix-CLI 2.5 for windows to connect to an INNFORMIX-SE database on a UNIX machine. Also I'm using Power Builder to build my application. The problem is that Power Builder tries to use certain sintax that the SE server does not support such as using "varchar" variables. I think that the problem can be in the configuration of INFORMIX-CLI. How does I-CLI knows that the engine on the other side is a SE enchine and not an ONLINE engine. I use "sesoctcp" protocol but I dont think its enough. Any help would be appreciated!!!! Thanks J Carlos