Copying specified columns from one workbook to a separate workbook containing uniquely named columns in another workbook.

I currently have an excel source workbook that contains data in some of the columns that needs to be copied to specific columns in a target workbook where the column names in the target workbook don't always match the column names in the source workbook. Basically, I need a macro to map that columns in the source workbook to the specified columns in the target workbook. I can have both workbooks open at the same time when the macro is run.