I'm not quite sure what you're asking... you mean you want to increase the size of the icons on the desktop area, and leave the ones on the taskbar the same size? iirc the size of the icons on the taskbar/ panel area is determined by how big you set the panel to be in kcontrol > desktop > panels, whereas the icon size is determined in kcontrol > icons > advanced and then set the filemanager/ desktop option to a larger size. Sorry but that's what works on my pc.
