A family of Microsoft spreadsheet software with tools for analyzing, charting, and communicating data.
With a defined name of Name1 identifying a vertical contiguous range of cells 1 column wide suitable to being the source for a data validation dropdown, this worked for me.
Sub Test()
Dim v As String
v = "Name1"
abc v
End Sub
Sub abc(LIST_NAME As String)
With Selection.Validation
.Delete
.Add Type:=xlValidateList, AlertStyle:=xlValidAlertStop, Operator:= _
xlBetween, Formula1:="=" & LIST_NAME
.IgnoreBlank = True
.InCellDropdown = True
.InputTitle = ""
.ErrorTitle = ""
.InputMessage = ""
.ErrorMessage = ""
.ShowInput = True
.ShowError = True
End With
End Sub