What are you trying to solve?  If you want the keyboard to generate lower case letters,  you will probably want to look at the CAPS LOCK setting under the keyboard in the Wavelink config utility.
http://www.wavelink.com/download/Downloads.aspx?DownloadFile=22847&…

If you are trying to get the barcodes to decode in upper case:

1. If you are generating the barcodes,  you can generate them with Upper Case letters.

2. If that's not an option,  the solution would depend on what application you are using to talk to the scanner.  If you are using the TelnetCE client,  I think you could probably define a scan handler within your Wavelink config to translate lower case to upper case.  I don't see a way within Wavelink to globally tell it to translate to all caps,  but maybe someone will correct me.   I tried the below scan handler (Scanner/Common/Scanhandler within the Wavelink config app),  and it seems to work fine (up through C).  I think you would have to expand on this for the whole alphabet.  A(0)[RaA]A(0)[RbB]A(0)[RcC]

3. If you are using datawedge,  in the configuration you could do "Basic Format/Send Data/As Upper Case".

You can actually use Datawedge with Wavelink if you go into the scanner settings in the Wavelink configurator tool and set Scanner/Common/No Scanner configuration.  I would suggest not doing this unless you really have no other option though.  If you use datawedge rather than Wavelink to control the scanner,  you lose some control over the scanner and the user will always need to have the proper field in focus on the screen.  Performance may also suffer.  It will usually be better to let Wavelink control the scanner if that's the app you are using.