Good news!
You line of code works in this context:
Sub qwerty()
Dim firstSpec As Long, lastSpec As Long
Set target = Cells(1, 7)
firstSpec = 1
lastSpec = 3
Range(Cells(firstSpec, 7), Cells(lastSpec, 7)).Sort Key1:=target, Order1:=xlAscending, Header:=xlGuess, OrderCustom:=1, MatchCase:=False, Orientation:=xlTopToBottom
End Sub
If you are getting errors, check the values for firstSpec, lastSpec and target