When using the OLEDB VBO, you will be able to specify the columns you want to pull from the source (which I assusme is Excel).
If you want to actually delete the column from Excel instead, try the Delete action in the Excel VBO. I have never used that action, but check the VBO Help (the blue "?" icon) and see if it will work for a column.
You could also try to load the Excel worksheet into a collection, then use the Delete Column action of the Utility - Collection Manipulation VBO to remove the column in question.
I hope that one of these options will lead you to a solution.
Best Regards.