new to macros- how to name and save excel document

[CFJ4858]

I'm in uncharted territory. I know nothing about macros or vba. But I watched a Mr. Excel video and figured out how to create a macro to auto sequential number electronic requisitions. I also figured out how to name, save and clear via a macro. I want to edit the "name" portion of macro as it only saves and names by invoice number which will not help when I need to retrieve it. I want to add the cells containing the date and name of vendor to the saveas range. How do I do this??

 

[CFJ4858]

This is what I have for command so far but I know the NewFN line is wrong. Cell O4 is invoice #, cell M11 is vendor name, cell E54 is date. That's how I want the sheet named. Help???
Sub SaveInvWithNewName()
Dim NewFN As Variant
' Copy Invoice to a new workbook
ActiveSheet.Copy
NewFN = "C:blah blah blah" & Range("O4, M11, E54").Value & ".xlsx"
ActiveWorkbook.SaveAs NewFN, FileFormat:=xlOpenXMLWorkbook
ActiveWorkbook.Close
NextInvoice
End Sub