how to use 'aspnet_Membership_CreateUser' directly through T-SQL

I would like to be able to use the stored procedure 'aspnet_Membership_CreateUser' directly through T-SQL code (instead of going through .Net wrappers) because I need to automate the creation of hundreds of users.

aspnet_Membership_CreateUser has among others the following parameters:  @Password, @PasswordSalt, @PasswordAnswer.
 
I assume that the @Password and @PasswordAnswer have to be encrypted using the @PasswordSalt

I have been unable to find documentation that explains
 
1. how to create the passwordsalt or where to retrieve it from
2. how to hash/encrypt the password and the security answer. 
   Is there another SP that does that?

Any help would be greatly appreciated.
 
Roberto
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