as this...
Dim varRbtnNm = "Radiobutton1"
select case(varRbtnNm)
case "Radiobutton1"
Radiobutton1.checked = true
case "Radiobutton2"
Radiobutton2.checked = true
end select
OR
Dim varRbtnNm = "Radiobutton1"
DirectCast(Me.Controls.Find(varRbtnNm,true).GetValue(0),RadioButton).Checked=True
Happy Coding!
:)