Create tempfield in definition expression to use in REST Service

[BrianO_keefe]

I'm asking if it is possible (not smart) to create a tempfield in an MXD Definition Expression that creates a tempfield which is a concantenation of a few other fields that will translate over to the REST service created by said MXD?

So to clarify. I want to do the following:

1. Create MXD using Feature Class X
2. Create Definition Expression that generates a TEMP FIELD (using SQL).
3. Temp Field will be a concantenation of fields A + B + C
4. Share MXD as a Service.
5. Create Webmap.
6. Use TempField from REST Service in Webmap.

Is this possible?