Unique index column as a foreign key in another table

I have one table say "client data" with 'ID' as surrogate key (Primary key) with autogenerated integer and it has a column as "client ID" of type 'nvarchar'. It was indexed as unique and so i can use this as a foreign key in another table. I have created an another table with a foreign key as "clientID" from client database table. Everything looks good in database. Now comes to Appian, I have created a Client data CDT and child table CDT and mapped as one to many relationship. When i publish the data store it is asking to make a change in the child table for creating the constraint with "ClientID". So my understanding is the primary key integer "ID" from client table is going to create as foreign key in the child table. But I don't want 'ID' as a foreign key instead i want to map the CDT's with indexed "ClientID" as foreign key. 

Any suggestions for this scenario? Any best syntax for the annotations?

FYI, we use microsoft SQL server as a database.