I think we have been putting them in promptsets since V9? I could be wrong.
If you code it into the promptset object itself, then just put it in as the default value.
Here is a working example of how to do it from the job. Note that the three fields with variables are showing the variable names (e.g. SERVER#). This is accomplished by toggling the field, which is accomplished by clicking on the fields label. If you don't toggle the field, then your string is not resolved.
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