How to Select a Whole Column Using Cells(1,1) Style?

In the macro below, how would I convert "Columns("B:B").Select" to the "Cells(1,1)" approach so that I can start using variables and delete as many columns as I want? I've tried the obvious substitutions but seem to have the syntax slightly wrong.

Thank you.

 Sub Step2A()
'
' Step2A Macro
' Deletes two columns

'
    Columns("B:B").Select
    Selection.ClearContents
    Columns("C:C").Select
    Selection.ClearContents
End Sub