I am creating a spreadsheet with data that I will be uploading into salesforce.com, so I'll be saving the spreadsheet as a .csv file. I have many columns where I have data validation referenced to item lists that reside on another sheet. Easy enough. Select and move on.

However, I need to be able to make multiple selections of data (all within the same list) in one particular column. This is simply a selection of what type of account the record is, (i.e., retail, wholesale, internet, catalog, other). If the account is involved in multiple business activities, I need to be able to select each of those to fully explain the type of account.

Is there a simple way this can be accomplished?