Multiple Selection Data Validation and Placement of Selection.

I have a program in excel that allows me to do analysis/summarize data on one form by searching for terms through the use of drop down lists using data validation. I would like to be able to select multiple factors and have those selections inserted into a different column with each selection in a different row. I am able to do that with the following code adapted from the contextures website:

Option Explicit
Private Sub Worksheet_Change(ByVal Target As Range)
On Error GoTo exitHandler

Dim rngDV As Range
Dim lRow As Long
Dim lCol As Long
Dim cRow As Long

lCol = Target.Column 'column with data validation cell

If Target.count > 1 Then GoTo exitHandler

On Error Resume Next
Set rngDV = Cells.SpecialCells(xlCellTypeAllValidation)
On Error GoTo exitHandler

If rngDV Is Nothing Then GoTo exitHandler

If Intersect(Target, rngDV) Is Nothing Then
   'do nothing
Else
    If Target.Value = "" Then GoTo exitHandler
    Application.EnableEvents = False
    Select Case Target.Column
       Case 10
        If Target.Offset(0, 18).Value = "" Then
           lRow = Target.Row
        Else
            lRow = Cells(Rows.count, lCol + 18).End(xlUp).Row
    End If
            Cells(lRow, lCol + 18).Value = Target.Value
    End Select
End If

exitHandler:
  Application.EnableEvents = True
  
End Sub

My data validation list consists of jobs: Welder, Mechanic, and Janitor. (and many other fields)
If Welder is selected, this places Welder in another column (column 18). If it is selected again, then it gets inserted into the same column and row below it. My problem is, if I were to select Welder twice, I would like it to remove the "Welder" from the column, rather than placing another instance of it in there.

I have a decent amount of experience coding in R, but very little in VBA, and writing loops are very foreign for me. I have a general strategy how I might approach this sort of problem in R, but it will do me no good in there . Thanks in advance for your time,

Lucas Smith