Nonsense. There's a slider called 'Exposure'
Try reading (more slowly) what I wrote:
There is nothing in LR (despite the name) that adjusts exposure. Again, despite the name, the slider has NOTHING to do with exposure. Exposure only takes place at capture.
Quite what the OP means by "the dot in the sliver and rotate scroll wheel" is less clear.
Try reading (more slowly) what I wrote:
Can you show a screen capture of what you're referring to?