|You have no knowledge about batch scripting, your script is meaningless.|
if /I "%1"=="copy" if exist %2 (copy %2 D:\ & goto :EOF)
echo. Missing or invalid parameters: %*
:EOF is the builtin exit point, you don't have to declare it. To know about a command type /? after its opcode, e.g. if /? and never code a command on the same row of its label. i.e.