Like Pabster said. If you want a piece of MP3 at higher than 128kbps you need to get a CD or an MP3 that is higher.
Upsampling does nothing...that MP3 only has 128kbps, you can give it room for 192kbps (larger file size), but it won't use it.
That's like moving from 128MB of RAM to 192MB when your system isn't even making full use of the 128MB. The extra is just unused wasted space.