How to Detect an Exam Grade that Contains a * When Using VLOOKUP

When I try to detect a grade that is followed by a * e.g. A* it sees this as a wild card and counts all values that contain A. In the example I have worked around this but I wondered if there is an actual way of detecting * grades directly without resorting to manipulation?
I have included a spreadsheet with data.
Many thanks if you are able to help.