functional index using siebel tools

Is there any way we can create functional index from siebel tools.

We had performance issue with EAI service which was querying a table S_PER_COMM_ADDR   ADDR column which resulted in > 60 s query time.

When the query was analyzed by DBA he suggested and created index

create index  S_PER_COMM_AD_IDX on  S_PER_COMM_ADDR(UPPER("ADDR"));

I checked i cannot create this type of Index in siebel tools there is also (Doc ID 1562386.1) which says this

We are on 15.18 patchset and Oracle 12.1 c oracle database version.

If we let DBA create the index from outside siebel tools or suppose i create outside siebel tools will ddlsync try to remove this index ? thats what we dont want because this change will be done in all pre prod environments.