VBA To Search Group Of Cells And Input Message If Value Is Missing From Group?

I am trying to write VBA code that groups cells between blank rows and inserts a message if a string of text (a name) is missing from the entire group. I want the code to search cells in column A and group the cells between blank cells. Use the name I input in an input box as the search criteria and insert a message in the Column C next to the last blank cell in the group and then move on to the next group and highlight the cell in red with bold text. I am including a spreadsheet with an example of what the sheet should look like before and after the code is run.