VBA Finding the next column based on an input value

Question

In a program that I\'m trying to write now I take two columns of numbers and perform calculations on them. I don\'t know where these two columns are located until the user tell

Answer 1

Here are two functions that will help you dealing with columns > "Z". They convert the textual form of a column to a column index (as a Long value) and vice versa:

Function ColTextToInt(ByVal col As String) As Long
    Dim c1 As String, c2 As String
    col = UCase(col) 'Make sure we are dealing with "A", not with "a"
    If Len(col) = 1 Then  'if "A" to "Z" is given, there is just one letter to decode
        ColTextToInt = Asc(col) - Asc("A") + 1
    ElseIf Len(col) = 2 Then
        c1 = Left(col, 1)  ' two letter columns: split to left and right letter
        c2 = Right(col, 1)
        ' calculate the column indexes from both letters  
        ColTextToInt = (Asc(c1) - Asc("A") + 1) * 26 + (Asc(c2) - Asc("A") + 1)
    Else
        ColTextToInt = 0
    End If
End Function

Function ColIntToText(ByVal col As Long) As String
    Dim i1 As Long, i2 As Long
    i1 = (col - 1) \ 26   ' col - 1 =i1*26+i2 : this calculates i1 and i2 from col 
    i2 = (col - 1) Mod 26
    ColIntToText = Chr(Asc("A") + i2)  ' if i1 is 0, this is the column from "A" to "Z"
    If i1 > 0 Then 'in this case, i1 represents the first letter of the two-letter columns
        ColIntToText = Chr(Asc("A") + i1 - 1) & ColIntToText ' add the first letter to the result
    End If
End Function

Now your problem can be solved easily, for example

newColumn = ColIntToText(ColTextToInt(oldColumn)+1)

EDITED accordingly to the remark of mwolfe02:

Of course, if you are not interested in the column names, but just want to get a range object of a specific cell in a given row right beneath a column given by the user, this code is "overkill". In this case, a simple

 Dim r as Range
 Dim row as long, oldColumn as String
 ' ... init row and oldColumn here ...

 Set r = mysheet.Range(oldColumn & row).Offset(0,1)
 ' now use r to manipulate the cell right to the original cell

will do it.