Alternatively for button names you could use
"$parentbtn" .. index
$parent will be replaced with the name of the buttons parent frame. It's the same as:
Lua Code:
DeathKnightChatScrollFrame.buttons[index] = CreateFrame("Button", DeathKnightChatScrollParent:GetName() .. "btn" .. index, DeathKnightChatScrollParent, "OptionsListButtonTemplate")
It assumes the parent frame has a name which seems likely given you're naming the buttons.