VLOOKUP match to Last Name OR Last Name, First Name

Please see the attached.

I end up with tons of text data in the Name column of the DataEntry Sheet, in either Last Name or Full Name (Last, First) form. I need a VLOOKUP formula in the Desired Results column of the DataEntry Sheet that will produce a match to the Employee ID from the Employee ID column of the Employee Master List Sheet, no matter which of the two forms of Name appear in the Name column of the Data Entry sheet.

In the case of data entry in the Name column of the Data Entry sheet, the VLOOKUP doesn't need to care about first name. Only looking to match to Employee ID if the last name is a match.