I haven't used the API in a while but I'm pretty sure the problem is with the line that contains "field"...
Firstly, the option to add is the command's full option, which in this case uses the syntax fielname = value.
Secondly, I believe you don't need the double quotes.
So your line should be something like that:
cmd.addOption( new Option( "some field name=some valid value for this field" );
Note that the double quotes are around the whole option, and that could have been stored in a string variable.
