Well, I may be mistaken, but it looks like you are not supplying the dictionary file; you are supplying the Dynamics.set file. The "set" file is basically a file that tells GP where the dictionary files are located. Open it with notepad, and you will see the list of dictionaries available, their id's, and locations.
That is the information you need to pass to the utility to get your assembly.
[edit]
Sorry not awake yet, I meant in previous post, you need to pass that ID number (located in the .set file) to get the assembly. You can leave out the .set file. It is used by default, unless you have a separate one with different dictionaries to be used.