Vlookup from another workbook Using R1C1 Notation

Hi,

I am building a macro to open a workbook and import data from that workbook using VLOOKUP.

I am getting a Run-time error '13' Type mismatch

The code uses FileDialog to prompt user to select the file.
Then I have used variables to store the workbook name and sheet name.
I then use those variables to set range variables to plug into the VLOOKUP formula.
The line of code triggering the error is the .formulaR1C1 line.

Any help to figure out what is wrong would be appreciated.

Set wb = Workbooks(fullpath)
    Set ws = wb.Sheets(1)
    lastcolumn = ws.Cells(1, ws.Columns.Count).End(xlToLeft).Column
    lastrow = ws.Cells(ws.Rows.Count, 1).End(xlUp).Row
    lcOEF = wsOEF.Cells(1, ws.Columns.Count).End(xlToLeft).Column
    lrOEF = wsOEF.Cells(ws.Rows.Count, 1).End(xlUp).Row
    Set headerMRP = ws.Range("A1", Cells(1, lastcolumn))
    Set tblMRP = ws.Range("A2", Cells(lastrow, lastcolumn))
    Set importMRPRange = wsOEF.Range(wsOEF.Cells(6, 121), wsOEF.Cells(lrOEF, 133))
    
    With importMRPRange
        .FormulaR1C1 = _
        "=VLOOKUP(RC1," & tblMRP & ",MATCH(R5C," & headerMRP & ",0),FALSE)"
        .Value = .Value
    End With

Thank you for that reply. That solved the error message but the formula that writes to the range is missing the reference to the new workbook so I get #n/a in the cells. Any idea why that might be happening?

Norie, that was awesome. That did the trick. I can't thank you enough.