Perform VLOOKUP to the LEFT with an approximate (TRUE, 1) match - excel

Question

I've got this VBA code that I've used to perform a VLOOKUP to the LEFT (I've found it on MrExcel and edited so that the lookup_value could be any type of data):
Public Function VLOOKUPLEFT(lookup_value As Variant, table_array As Range, col_index_num As Integer, Optional range_lookup As Boolean = False) As Variant
Dim wk As Workbook
Dim ws As Worksheet
Dim valFind As Range
Set wk = Application.ActiveWorkbook
Set ws = wk.ActiveSheet
Set valFind = table_array.Find(What:=lookup_value, LookIn:=xlValues, LookAt:=xlWhole, SearchOrder:=xlByRows, _
MatchCase:=False, SearchFormat:=False).Offset(0, -1 * col_index_num)
VLOOKUPLEFT = valFind.Value
End Function
As you can see, the col_index_num is not referenced anywhere else in the code, because I do not know where to put it exactly.
Apprently, the .Find method does not allow approximate matches. I thought it'd be SearchFormat or LookAt, but the documentation is clear on them, as they regard something totally different:
SearchFormat: This indicates whether the value to be searched should be in a specific format (like bold or italics) or not. If the search value should follow a formatting technique, this argument is specified as true, otherwise it is false. The default value of this argument is false.
LootAt: This decides whether to match the content of the entire cell (exact match) or to match a part of the cell content (partial match). The constants are xlWhole and xlPart for exact and partial matches respectively. The default value of this argument is xlPart.
Of course, I know I could simply use INDEX/MATCH/MATCH or XLOOKUP. But I wonder if there's a way to implement this, for learning purposes as well.
I've tried to search for a value that would give me an approximate match, but of course it returned the #VALUE! error in Excel. This is because the code does not yet allow for an approximate match.

Answer 1

Public Function VLOOKUPLEFT(lookup_value As Variant, table_array As Range, col_index_num As Integer, Optional range_lookup As Boolean = False) As Variant
Dim wk As Workbook
Dim ws As Worksheet
Dim valFind As Range
Dim counter As Long
Dim formula_col As Integer
Set wk = Application.ActiveWorkbook
Set ws = wk.ActiveSheet
counter = 0
If range_lookup = TRUE Then
Do
Set valFind = table_array.Find(What:=lookup_value, LookIn:=xlValues, LookAt:=xlWhole, SearchOrder:=xlByRows, _
MatchCase:=False, SearchFormat:=False)
If Not valFind Is Nothing Then
Exit Do
End If
For i = 1 To table_array.Rows.Count - 1
If lookup_value >= table_array(i, table_array.Columns.Count).Value And _
lookup_value < table_array(i + 1, table_array.Columns.Count).Value Then
lookup_value = table_array(i, table_array.Columns.Count)
Set valFind = table_array.Find(What:=lookup_value, LookIn:=xlValues, LookAt:=xlWhole, SearchOrder:=xlByRows, _
MatchCase:=False, SearchFormat:=False)
Exit Do
End If
Next i
counter = counter + 1
If counter >= table_array.Rows.Count Then
Exit Do
End If
Loop
Else
Set valFind = table_array.Find(What:=lookup_value, LookIn:=xlValues, LookAt:=xlWhole, SearchOrder:=xlByRows, _
MatchCase:=False, SearchFormat:=False)
End If
If Not valFind Is Nothing Then
formula_col = table_array.Columns.Count - col_index_num
VLOOKUPLEFT = valFind.Offset(0, -1 * formula_col).Value
'If you want the columns to count from right to left, substitute "-1 * formula_col" with "(-1 * col_index_num) + 1" in the second argument of the .Offset method'
Else
VLOOKUPLEFT = CVErr(xlErrValue)
End If
End Function