How can I create my own passwords for the users, instead of using "UserController.GeneratePassword()"?

I create a new user using the following code:

            Dim user As New UserInfo()
            user.Profile.InitialiseProfile(PortalId)

            user.Username = sUserName
            user.Email = Me.txtEmailAddress.Text
            user.DisplayName = sCustomerName
            user.FirstName = sCustomerName
            user.LastName = ""
            user.PortalID = PortalId

            user.Profile.FirstName = sCustomerName
            user.Profile.LastName = ""
            user.Profile.Unit = ""
            user.Profile.Street = Me.txtAddress.Text
            user.Profile.City = Me.txtCity.Text
            user.Profile.PostalCode = Me.txtZip.Text
            user.Profile.Telephone = Me.txtPhone.Text
            user.Profile.PreferredLocale = "es-US"

            ' user.Membership.Password = "abcdef"
            sUserPassword = UserController.GeneratePassword(6)
            user.Membership.Password = sUserPassword
            user.Membership.UpdatePassword = True
            user.Membership.Email = Me.txtEmailAddress.Text
            user.Membership.Approved = False
            user.Membership.PasswordAnswer = ""

            Dim uscre As DotNetNuke.Security.Membership.UserCreateStatus
            uscre = UserController.CreateUser(user)

user.Membership.Password = "abcdef"  ----- This did not work.

thanks,

Dean