creating Aliases in Membership

I have SQL 7.0 EE using MSCS solution & LDAP servers using WLBS.

How to create aliases for users already created?

Can it be done through membership ? or

can it be done using SQL scripts?

Kindly suggest a method of creating aliases?

Isthere any KB article on this problem? or step by step instructions for doing the same?

Thanks is advance

Venkatesh