How to map a cell value to another cell with IF condition - excel

Question

Suppose I have a table like this in excel -
+-------------+----------+------------+
| Google Name | D11 Name | Entry |
+-------------+----------+------------+
| REN | MLR | |
| THU | SDT | |
| SIX | SDS | |
| HOH | HBH | |
| STR | ADS | |
| HEA | BRH | |
| PRS | PS | |
| STA | MLS | |
+-------------+----------+------------+
Now I will enter something in Entry column. If the value matches with Google Name value it should change to corresponding D11 Name value. Which means this -
+-------------+----------+------------+
| Google Name | D11 Name | Entry |
+-------------+----------+------------+
| REN | MLR | SIX -> SDS |
| THU | SDT | |
| SIX | SDS | |
| HOH | HBH | |
| STR | ADS | |
| HEA | BRH | |
| PRS | PS | |
| STA | MLS | |
+-------------+----------+------------+
If I enter SIX final entry will be SDS, -> is for explaining purpose only.

Answer 1

If you want to change a typed input to a values retrieved from a lookup, you need VBA and a Worksheet_Change event driven sub procedure.
Open the worksheet's private code sheet (right-click worksheet name tab and View Code) then paste in this code.
Option Explicit
Private Sub Worksheet_Change(ByVal Target As Range)
If Not Intersect(Target, Range("C:C")) Is Nothing Then
On Error GoTo sub_exit
Application.EnableEvents = False
Dim t As Range, m As Variant
For Each t In Intersect(Target, Range("C:C"))
m = Application.Match(t.Value2, Range("A:A"), 0)
If Not IsError(m) Then
t = Cells(m, "B").Value2
End If
Next t
End If
sub_exit:
Application.EnableEvents = True
End Sub