dynamicly hide/show column in a grid

i modify an existing application to give it a one to many relationship. on an edit form, it has user's details and one of the field (Access) has UDC values as below. People will select 1 or 2 (there are a lot of UDC values, below are just example). 

Code     Description 1                                        Description 2

1           View all people in a department             HMCO

2           View all people in a company                CO

To create a many relationship, i created a new table and it will have 2 columns, department and company columns besides the userid column. If Access is 1 then the HMCO column will be filled in with 1 or more records.  If Access is 2 then the CO column will be filled in with 1 or more records.