With DAO, you can change modify it programmatically:
'**************************************************
Sub exaModifyLinkedTable()
'DAO DDL example
'demonstrates modifying a table, fields, properties
Dim db As DAO.Database
Dim tdf As DAO.TableDef
Dim fld As DAO.Field
' Create the table and a field
Set db = OpenDatabase("c:\path\to\MyDatabase.mdb")
Set tdf = db.TableDefs("MyTable")
Set fld = tdf.CreateField("NewField", dbText, 50)
' Set field properties
fld.AllowZeroLength = True
fld.DefaultValue = "Unknown"
fld.Required = True
fld.ValidationRule = "Like 'A*' or Like 'Unknown'"
fld.ValidationText = "Known value must begin with A"
' Append field to Fields collection
tdf.Fields.Append fld
End Sub
'**************************************************
You can also modify a table using SQL:
'**************************************************
Sub exaModifyLinkedTableSQL()
'SQL DDL example
'Alter Table example adds several fields to an existing table
Dim db As DAO.Database
' Create the table and a field
Set db = OpenDatabase("c:\MyDatabase.mdb")
db.Execute "alter table MyTable add Newfield1 text(10);"
db.Execute "alter table tblResults add Newfield2 text(2);"
db.Execute "alter table tblResults add Newfield3 date;"
End Sub
'**************************************************
However you cannot set some of the properties with SQL.