There is a way. Get someone's profile files (who has played online for once) from their Documents\Battlefield 2142\Profiles - then open the file 'profile.con' with notepad. It's gonna be like this:

LocalProfile.setName "???"
LocalProfile.setGamespyNick "???"
LocalProfile.setEAOnlineMasterAccount "???"
LocalProfile.setEAOnlineSubAccount "???"

Remove whatever's in between those quotation marks and alter it to your liking. The password usually remains to be the old one, or the same as your account name. For Example:

LocalProfile.setName "Insertnamehere"
LocalProfile.setGamespyNick "Insertnamehere"
LocalProfile.setEAOnlineMasterAccount "Insertnamehere"
LocalProfile.setEAOnlineSubAccount "Insertnamehere"