Some things of top of my head.
Method 1.
Application.Union(Range("a1"), Range("b1"), Range("d1"), Range("e1"), Range("g1"), Range("h1")).EntireColumn.Select
Method 2.
Range("a1,b1,d1,e1,g1,h1").EntireColumn.Select
Method 3.
Application.Union(Columns("a"), Columns("b"), Columns("d"), Columns("e"), Columns("g"), Columns("h")).Select