Hi Vinod,
As far as I'm aware you cannot set one of the parameters to be a checkbox in a search help created through se11. You could investigate using a search help exit but I don't think these offer possibilities to change the selection dialog of the search help. You could off course develop your own modal dialog or try calling a function module like F4IF_INT_TABLE_VALUE_REQUEST to meet your requirements but then you wouldn't have the easy integration into all places that use data elements that use this search help, e.g. se16. I suppose it depends how important this requirement is to you given that it is purely cosmetic vs. in how many places you intend to use this search help.
Regards,
Jamie.