Grabweb expert doesn't trade. It is a different kind of expert. It is just fetching the news from Forecfactory.com website and writes them into CSV file in 'experts/files' directory.
The following is a simple example of how to use Swiss Ephemeries DLL in MT4. Copy astro1.mq4 to /experts/ directory under your MT4 directory and swedll32.dll to /experts/libraries/ directory under your MT4 directory and it should work.