Issues with using an intersect(replace(join())) sub - vba

Question

I'm having some problem with the following code.
rng is a range that represents quite a large table. E.g. A1:G600. refArr is a list of row numbers. I need the following code to pass back a range so that just the rows from refArr can be selected out of rng.
However, when my refArr is too long (i.e. when it has over 54 items exactly) it gives me an error.... Any ideas why this would be the case?
Function RangeSelector(rng As Range, refArr As Variant) As Range
Set RangeSelector = Intersect(rng, rng.Range("A" & Replace(Join(refArr, ","), ",", ",A")).EntireRow.Offset(1))
End Function

Answer 1

The problem is that the maximum string length for Range is 255. We can get around that by using Union.
Notice that Range.address will only return 255 characters even if the actual address is much longer
In the test I use RangeSelector to select every other row from 1 to 600
Test
Sub TestRangeSelector()
Const MAXROWS As Long = 300
Dim refArr(1 To MAXROWS), x As Long
Dim Target As Range
For x = 1 To MAXROWS
refArr(x) = x * 2
Next
Set Target = RangeSelector(Range("A1:G600"), refArr)
Target.Select
Debug.Print "Absolute Address: "; Len(Target.Address), Target.Address
Debug.Print "Relative Address: "; Len(Target.Address(False, False)), Target.Address(False, False)
End Sub
RangeSelector
Function RangeSelector(rng As Range, refArr) As Range
Dim s As String, Target As Range, v As Variant, x As Long
For x = LBound(refArr) To UBound(refArr)
s = s & refArr(x) & ":" & refArr(x) & ","
If x = UBound(refArr) Or Len(s) >= 251 Then
s = Left(s, Len(s) - 1)
If Target Is Nothing Then
Set Target = rng.Range(s)
Else
Set Target = Union(Target, rng.Range(s))
End If
s = ""
End If
Next
Set RangeSelector = Intersect(rng, Target)
End Function