Try this Huawei calculator. When you insert the modem with other SIM, Huawei will ask you for this code. I don't know any tool to unlock the modem definetely.
I posted the calculator here: http://www.finetopix.com/showthread.php?t=8008
Once you have the code, you can either insert another SIM card and it will ask you for the code, or, if you search around on google, you should be able to find a tool which enters the code. I had this app before, but I can't find it now.
Bookmarks