Excel VBA returning User details

I am trying to create an excel spreadsheet that looks using VBA code at the User's details logged into the network via the pc and returns the information to a cell on the spreadsheet.

I have looked at the environ function and can use that to display username etc however my organisation allocates employees a numberical login e.g. 123456 where I want the actual user's name e.g. Williams, David.

when logged into the computer I can see the users name I want on the top of the start menu. This appears to be retrieved from MS exchange email account without the word mailbox - Williams, David. Can someone tell me how to use this reference to display in Excel the same way it does on the start menu.