Selecting Array of columns by Header Names

[benntw]

Need help to select multiple columns by header names. The next action would be to clear contents below each header name listed in the array.
I have my range code to use with it. Row 4 is the starting point of clearing contents. I do not want to delete the entire row. Just clearing any column that I would put in an array

Set lastCell = BuildRangeToLastCell(InRS.Cells, 4, 1)

Thank you for the help.