I assume your source flat file is a variable size one as opposed as a fixed size one.
If my assumption is correct I wouldn't be surprised if you end up loading the file as it is, probably first_name into Name_1 and last_name into contact_name then run a simple procedure to update the loaded rows formatting both columns as you need.
If my assumption is incorrect and your source file is a fixed size one just map the columns by position.
Disclaimer: Advice is provided to the best of my knowledge but no implicit or explicit warranties are provided. Since the advisor explicitly encourages testing any and all suggestions on a test non-production environment advisor should not held liable or responsible for any actions taken based on the given advice.