How do I pass a function argument to Send?

I am thinking of something like:

Interact(controlName, activationTime)
{
    Sleep 100                           ; Small pause
    Send {controlName Down}             ; Hold interact control down
    Sleep activationTime                ; Wait for <activationTime> seconds
    Send {controlName Up}               ; Let go of interact control
    Sleep 100                           ; Small pause
}


OpenMap()
{
    Interact(Lbutton, 1200)
}

Would that work, or would I need to decorate the label “Lbutton” and/or the variable name controlName, like e.g.

    Send {%controlName% Down}               ; Hold interact control down

Or would I need to transmit “Lbutton down” (plus a corresponding “Lbutton up”) to Interact (adding another parameter for that?