To do this all you got to do is open regedit. Then navigate to hkey_classes_root/*/shell. Right click on "shell" and select "new" and then select "key" and then name it. What ever you name this key is what will show up on the right click menu. So if you name it "This is a test key" then that is what will show up on the right click menu.
Next, right click on the key you created and select "new" and then "key" again. This time name this key specifically "command". Once you have named it, you edit the value. I have a script called reverse.pl, so when I edit the value, i put in there "C:\perl\bin\perl.exe C:\users\james\dropbox\scripts\reverse.pl %1" the when I right click a file, it will have that option to run that script per each right clicked file.

Once you do this, you should be able to right click any file, and the command will be right in right click context menu.