[VBA Excel] WorksheetFunction, passage d'arg

Function stdevBequalsC(plage As Range) '
Dim c
Dim chaine As String
Dim cpt As Integer

For Each c In plage
    If Range("B" & c.Row) = Range("C" & c.Row) Then
        cpt = cpt + 1
        If cpt = 1 Then
            chaine = chaine & "F" & c.Row
        Else
            chaine = chaine & ":F" & c.Row
            cpt = 0
            chaine = chaine & ","
        End If
        
    End If
    
Next c

chaine = Mid(chaine, 1, Len(chaine) - 1)

'    MsgBox WorksheetFunction.StDev(Range(chaine))

stdevBequalsC = WorksheetFunction.StDev(Range(chaine))

End Function

Function stdevBequalsC(plage As Range) '
Dim c As Range, myrange As Range, cpt As Integer
For Each c In plage
        cpt = cpt + 1
        If cpt = 1 Then
            myrange = Range(c.Address) ' ça coince ici
        Else
            myrange = Union(myrange, Range(c.Address)) 'et là
        End If
Next c

stdevBequalsC = WorksheetFunction.StDev(myrange) 
End Function

Sub selectPlage()
Dim lig As Long
Dim ligTest As Long
Dim derlig As Long
Dim mTarget As Range

    lig = 1
    ligTest = 1
    While Sheets(1).Range("B" & ligTest).Value <> ""
        If Sheets(1).Range("B" & ligTest).Value = Sheets(1).Range("C" & ligTest) Then
            Sheets(1).Range("J" & lig).Value = Sheets(1).Range("F" & ligTest).Value
            lig = lig + 1
        End If
    ligTest = ligTest + 1
    Wend
    
    Set mTarget = Sheets(1).Range("J1: J" & lig - 1)
    
    MsgBox stdevBequalsC(mTarget)
    

End Sub

Function stdevBequalsC(plage As Range)
   stdevBequalsC = WorksheetFunction.StDev(plage)
End Function