Is there a way to modify multiple record in one button ??

Typically these kinds of questions are possible, but require a Developer to come up with a method to do this.  An alternate approach which might be good enough for you would be to come up with a button which launch off a record and show all records which have the same Category as the representative record.  Then you would use Grid edit to do your updates.

Alternatively, there is a list of Developer Partners here http://quickbase.intuit.com/partners