Assigning range of cells results in Type Mismatch (Run-time Error 13) - excel

Question

I am trying to automate the population of a Vlookup formula, looking up values from one worksheet in another. There are two worksheets in the workbook, Suppliers and Products. The product code is looked up from the Products worksheet in the Suppliers worksheet.
This is the code:
Dim lastrow As Long
Sheets("Suppliers").Select
lastrow = ActiveSheet.UsedRange.Rows.Count
Dim SuppliersRnge As Range
Set SuppliersRnge = Range(Cells(2, 2), Cells(lastrow, 3))
' This next try was by declaring the first and last rows and columns in Suppliers sheet as variables and passing values to them (passing values not shown here)
' Set SuppliersRnge = .Range(.Cells(SupplierFirstRow, SupplierFirstColumn), .Cells(SupplierLastRow, SupplierLastColumn))
' This next try was by declaring the range as a static set of cells rather than using lastrow
' Set SuppliersRnge = Range("B2:C23")
' This next try was to pick cell references from currently active worksheet
' Set SuppliersRnge = .Range(.Cells(2, 2), .Cells(lastrow, 3))
' This next try was by fully qualifying the name of the worksheet from which the cell reference is drawn
' Set SuppliersRnge = Worksheets(Suppliers).Range(Cells(2, 2), Cells(lastrow, 3))
' Now switching to product sheet
Sheets("Products").Select
' Selecting cell in which vlookup will be added
Range("A4").Select
ActiveCell.FormulaR1C1 = "=VLOOKUP(RC[1],SuppliersRnge,2,FALSE)"
I am declaring SuppliersRnge as a range and using Set to pass to it the range of cells that need to be looked up.
I have tried to do it in five different ways (you will find four of the ways commented out above) with the same result, which is that the string SuppliersRnge literally gets used in the vlookup, resulting in a >#NAME? value where the result of the Vlookup should be.
When I run ?SuppliersRnge in the Immediate window, I get the Type Mismatch (Run-time Error 13).
If I run a Watch on the SuppliersRnge variable, it starts with a "Nothing" value then changes to a blank.
Any idea on where I might be going wrong? Thanks!

Answer 1

Formulas in VBA
Note the single quotes (around the worksheet name) which are only necessary if the worksheet name contains spaces, but it is good practice to use them always.
Option Explicit
Sub writeVLookupFormula()
Const sName As String = "Suppliers" ' Source
Const dName As String = "Products" ' Destination
Dim wb As Workbook: Set wb = ThisWorkbook ' workbook containing this code
Dim sws As Worksheet: Set sws = wb.Worksheets(sName)
Dim sLast As Long: sLast = sws.UsedRange.Rows.Count
Dim srg As Range: Set srg = sws.Range(sws.Cells(2, 2), sws.Cells(sLast, 3))
Dim dws As Worksheet: Set dws = wb.Worksheets(dName)
' R1C1-style
Dim dFormula As String: dFormula = "=VLOOKUP(RC[1],'" & sName & "'!" _
& srg.Address(, , xlR1C1) & ",2,FALSE)"
dws.Range("A4").FormulaR1C1 = dFormula
' Or:
' ' A1-style
' Dim dFormula As String: dFormula = "=VLOOKUP(B4,'" & sName & "'!" _
' & srg.Address & ",2,FALSE)"
' dws.Range("A4").Formula = dFormula
End Sub