Summary for those who might not want to read that much:
There is nothing to confuse. The very straight answer which I tested and it is working perrfect.
To send the command line argument to any JNLP is very simple.
command prompt > javaws -open space arg1 space arg2 ... space arg n JNLP url
Ex:
c:\>javaws -open arg1 arg2 arg3 c:\myjnlp.jnlp
But remember one thing, We can get the -open also as args[0] in main method, so just avoid args[0]. Also it is not possible to avoid -open with direct argument prepixed with -.