Defaulting Values into Select-Options field in SAP T-code View in WebDynpro ABAP

Hello Experts,

                      I have the requirement below to call the SAP T-code through Webdynpro and default the values . I am able to call the T-code and i was able to pass the value into the Control area but I am unable to pass the values into the Cost center field  .  Please find the code shown below. Thanks!! in advance.

CONCATENATE 'http://XXXXXX.edu:8000/sap/bc/gui/sap/its/webgui?~transaction=KSB1'

   '%20SVALD-VALUE=' gc_control

';KOSTL-SIGN =' gc_sign

';KOSTL-OPTION=' gc_option

';KOSTL-LOW=' gc_kostl

';KOSTL-HIGH=' gc_kostl

INTO URL.

*  call the url which we created above

   LO_WINDOW_MANAGER->CREATE_EXTERNAL_WINDOW(

   EXPORTING

   URL = URL

   RECEIVING

   WINDOW = LO_WINDOW ).

   LO_WINDOW->OPEN( ).

Thanks,

Vishnu