sqlserver-2005 application of user not accessing column to delete

Here is a Stack Overflow question that has the code you need (in the question):
 
http://stackoverflow.com/questions/1247147/how-to-make-ddl-trigger-for-a-specific-table[^]
 
Basically you create a DDL trigger at the database level that watches the ALTER_TABLE commands. Then, you use the XML EventData to look at which table is being modified and selectively block the action (unless you want to block the modification of every table in your database).