Created Unassigned: Syntax Error with VLookUp and/or Concatenate [9174]

Hi,

I've been using ClosedXML to read an Excel file (2010 version), and I get an error while reading the content of a cell containing this formula :

In Excel (french version) :
=RECHERCHEV(CONCATENER(D2;"-";F2;"-";H2;"-";I2;"-";J2;"-";K2);Buy!$A:$S;17;0)

In Visual Studio :
?oSht.Cell(idxRow, 12).FormulaA1
"VLOOKUP(CONCATENATE(D2,"-",F2,"-",H2,"-",I2,"-",J2,"-",K2),Buy!$A:$S,17,0)"

When I try to read the cell value, I get an error.

The error returned is this one : "Syntax Error" with no more comments.

The stack trace is :

à ClosedXML.Excel.CalcEngine.CalcEngine.Throw(String msg)
à ClosedXML.Excel.CalcEngine.CalcEngine.Throw()
à ClosedXML.Excel.CalcEngine.CalcEngine.Parse(String expression)
à ClosedXML.Excel.CalcEngine.ExpressionCache.get_Item(String expression)
à ClosedXML.Excel.CalcEngine.CalcEngine.Evaluate(String expression)
à ClosedXML.Excel.XLWorksheet.Evaluate(String expression)
à ClosedXML.Excel.XLCell.get_Value()

HResult : -2146233088

Is there a known problem with the VLOOKUP function, or CONCATENATE ?

Thanks in advance for your help

Damien