ps to pdf converter path in tcl/tk

I am trying to use the pdf export option under Accessories in orcad. I have a pdf converter installed. 

When I try to print I get "Postscript to pdf converter not found in path" 

How do I enter the path of ps to pdf converter in tcl/tk.

There are 3 options - Adobe distiller, gs to pdf and custom. I tried with distiller and gs to pdf. No luck.

I downloaded gs to pdf converter. But I don't know how to enter the path. It's a bit strange, its not the usual c:\....