SQLOLEDB exposes ITableDefinition::AddColumn allowing consumers to add a column to a SQL Server table.
When adding a column to a SQL Server table, the SQLOLEDB consumer is constrained as follows:
Consumers specify the table name as a Unicode character string in the pwszName member of the uName union in the pTableID parameter. The eKind member of pTableID must be DBKIND_NAME.
The new column name is specified as a Unicode character string in the pwszName member of the uName union in the dbcid member of the DBCOLUMNDESC parameter pColumnDesc. The dbcid eKind member must be DBKIND_NAME.