Hey,
You could use something like this ...
Option Explicit
Sub CreateFullName()
Dim cel As Range, rng As Range
Set rng = Range("A2:A10")
For Each cel In rng
cel.Offset(, 2).Value = cel.Value & " " & cel.Offset(, 1).Value
Next cel
End Sub
This is assuming some things. 1) Your range of Last Names are in A2:A10. 2) Your first names are in the corresponding rows in column B. 3) You have nothing in the corresponding rows of column C as that's where the concatenated values go. A formula would look like ...