Biller Direct and R/3

Hi,

We have installed SAP Biller Direct application on J2EE 620 engine integrated with SAP R/3 4.7 Enterprise (WAS 620). For user management security we will use ABAP stack.

The link of this Biller Direct Application will be provided on company's web portal (not SAP Ent. Portal). Once user click on link , Biller Direct application will open it another browser window.User must create their own user id and password.Other information will also be asked like Last Name ,first name, etc) during user id and password creation. Basically user will create their own user master record. (just think of it as you are creating an email account in Yahoo portal connected to R/3)

My question is :-

1) What configuration I need to do on J2EE and R/3 side so that user record will be created in R/3 when user creates it's own ID and password?

2)If I want to link LDAP with R/3, how I can link the LDAP with R/3 (user mapping ) will it be automatic, once the user creates it user id in web portal? OR do i have manually synch LDAP and R/3

I will appreciate your response

Thanks