How to add several values for a single key in Windows Registry

I'm trying to add an entry for AutoRun with value doskey selenium=java -jar C:\dev\selenium-server-standalone-2.45.0.jar to HKEY_CURRENT_USER\Software\Microsoft\Command Processor. However the AutoRun key has already a value (if %ANSICON_VER%==^%ANSICON_VER^% "C:\dev\ansi166\x64\ansicon" -p)

How can I solve this ?