I have been trying to write a procedure that checks if a selected cell is in
a range of cells.
I wrote the following code:

Sub intersct()
Dim xcell As Range
Dim a As String
Dim rng1 As Range
Dim rng2 As Range
Dim rng3 As Range

Set xcell = ActiveCell.EntireRow.Cells(1)
a = xcell.Text
Do While a = ""
Set xcell = xcell.Offset(-1, 0)
a = xcell.Text
Loop
costid = a
MsgBox (costid)
Set rng1 = Range(costid & "estsubvenrng")
Set rng2 = Range(costid & "estdescriptrng")
Set rng3 = Range(costid & "estamountrng")
Set isect = Application.Intersect(rng1, rng2, rng3)
If isect Is Nothing Then
MsgBox "nothing"
Else
MsgBox "Intersect"
End If



End Sub

When I run it I always get msgbox "Nothing" even when the selected cell is
within the range of cells.

What am I doing wrong?
Thanks