[Fizzlemizz]

A function with a single string parameter if needed.

It could be:

SlashCmdList["RAIDLOCKREPORT"] = function(msg) 
    if msg then
        DEFAULT_CHAT_FRAME:AddMessage(msg) 
    else
        DEFAULT_CHAT_FRAME:AddMessage("Working") 
    end
end
SLASH_RAIDLOCKREPORT1 = "/raidlockreport";
SLASH_RAIDLOCKREPORT2 = "/rlr";

if you type "/rlr 123" it would print 123.