Here's what I did. This is for *67, but you could do similar for any code.
1. In SYSTEM/NUMBERING PLAN/TOLL STRINGS/Q add "555" to the list. This is handy because we can tell the system to drop that string later by just not turning on ECHO EQUAL ACCESS rule.
2. In NUMBERING PLAN/DIAL RULES add new rule "add *67".
3. In NUMBERING PLAN/FACILITY GROUPS add new group. I called mine "BLOCK CLID". Under DIAL RULES ADD *67, Echo Toll Field, Echo 3 digits after toll field, Echo local address. Under TRUNK GROUPS use your PRI group.
4. In NUMBERING PLAN/ROUTE GROUPS add new group, I called mine BLOCK CLID, same as my FACILITY GROUP. Drag this new rule to the top of the list (ARS hunts top down). In this ROUTE GROUP set DIAL PATTERNS to "555+". In ROUTE GROUPS/FACILITY GROUPS add your new BLOCK CLID.
That's it, your routing is in place. From a phone dial 8 (assuming 8 is ARS, then dial 555 plus outside number. ARS sees a number starting with 555, uses that route group. Facility group grabs a trunk, dials *67, ignores 555 because it's equal access code, echoes all the other digits.
My phone has self-labeling keys, so I used the user web interface (only way to name the button) to create a station speed dial named BLOCK CLID, and put in 8555 as number. If you're using paper desi phones you could instead put in the sta spd by using the ONLINE MONITOR feature under VIEW in sys admin.