Change vlookup-range in function

Hello,

I want to create a function that looks in a certain range for a certain value

The name of the range is in cell B1, de value that needs to be looked up is ie cell A1. I have several ranges: BE_UP, BE_DOWN, NL_UP, NL_DOWN. They are al defined

In cell A1 I enter the value that I'm looking for
In Cell B1, I enter the value of the range that he needs looking in

first question: is it possible to do this with the norma vlookup-formula

Second question: in the code below, I tried it, but I do not get any value
 

Function VLOOKUPGV(oRNGSearch As Range, oRNGLookup As Range, iCol As Integer, bTemp As Boolean) 

Dim sRange As String
Dim dtLookup

VLOOKUPGV = Application.WorksheetFunction.VLookup(oRNGSearch.value, Application.Range(oRNGLookup.value), iCol, True)

End Function

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What is going wrong ?

Thank you very much