Add value from combobox onto multiple columns - excel

Question

I have created a combobox that has different cases seen below. The current formula works except that I would like to add a additional column that replicates the same value given to columns C and want to add it column R.
Ex. ComboBox
Select Current Month
I want to add 500 units to Column C and Column R based on the part that was searched for.
Private Sub cmdAdd_Click()
Dim irow As Long
Dim lastRow As Long
Dim iCol As String
Dim C As Range
Dim ws As Worksheet
Dim value As Long
Dim NewPart As Boolean
Set ws = Worksheets("Summary")
Set C = ws.Range("A7:A1048576").Find(What:=Me.PartTextBox.value, SearchOrder:=xlRows, _
SearchDirection:=xlPrevious, LookIn:=xlValues, LookAt:=xlWhole)
If C Is Nothing Then
'find first empty row in database
lastRow = ActiveSheet.UsedRange.Row - 1 + ActiveSheet.UsedRange.Rows.Count
irow = lastRow + 1
NewPart = True
Else
'find row where the part is
irow = ws.Cells.Find(What:=Me.PartTextBox.value, SearchOrder:=xlRows, _
SearchDirection:=xlPrevious, LookIn:=xlValues).Row
NewPart = False
End If
'check for a part number
If Trim(Me.PartTextBox.value) = "" Then
Me.PartTextBox.SetFocus
MsgBox "Please Enter A Part Number"
Exit Sub
End If
If Trim(Me.MonthComboBox.value) = "" Then
Me.MonthComboBox.SetFocus
MsgBox "Please Enter A Month"
Exit Sub
End If
If Trim(Me.AddTextBox.value) = "" Then
Me.AddTextBox.SetFocus
MsgBox "Please Enter A Value To Add Or Substract"
Exit Sub
End If
Select Case MonthComboBox.value
Case "Current Month"
iCol = "C" And "R"
Case "Current Month +1"
iCol = "N"
Case "Current Month +2"
iCol = "O"
Case "Current Month +3"
iCol = "P"
Case "Current Month +4"
iCol = "Q"
End Select
value = Cells(irow, iCol).value
With ws
.Cells(irow, iCol).value = value + CLng(Me.AddTextBox.value)
End With
If NewPart = True Then
ws.Cells(irow, "A").value = Me.PartTextBox.value
End If
If NewPart = True Then
ws.Cells(irow, "C").value = Me.AddTextBox.value
End If

Answer 1

I may recommend using an Array to store the columns.
Sub t()
Dim iCol()
Dim testStr$, myValue$
Dim iRow&
Dim ws As Worksheet
testStr = "Current Month"
Select Case testStr
Case "Current Month"
iCol() = Array("C", "R")
Case "Current Month +1"
iCol() = Array("N")
End Select
Dim i&
For i = LBound(iCol) To UBound(iCol)
myValue = Cells(iRow, iCol(i)).value ' WHAT SHEET IS THIS ON??
With ws
.Cells(iRow, iCol(i)).value = myValue + CLng(Me.AddTextbox.value)
End With
Next i
End Sub
You can add to the Case as needed. Note that you need to wrap the Next i after you're done working with a column, so it can see if there's a second one to run on.
Also, since you didn't include all the code, you may have to adjust the ranges. (note the myValue doesn't have a Sheet specified for what Cells() to use).