RestAPI for Assign Security Role to User

Hi, In Hyperion Cloud platform, am looking for 2 api. 1. User creation - myservice portal, want to create user for Planning and Budgeting. - Can this is achievable by using LDAP integration ? e.g. Create one LDAP group, whenever user added to same, it will create automatically in myservice. 2. As user created, want to assign the security role in budget application. Can master provide guidance on same ? Thanks Lokesh