administer MSSQL databases from Drupal 6
There is no support for MSSQL Server in Drupal 6, so it is higly unlikely that a module that can help you to administer your MSSQL databases exists.

You could maybe write your own, see MSSql or SQL Server Wrapper for custom module? for a possible way to connect to your database while still being able to rely on some API's provided by Drupal.