I have seen the use of prompts in SAS EG 4.2, actually in a demo. When you are in EG, it has the 'prompt manager' that allows you to build a prompt so when you execute your query (query builder) it does the prompt you just defined.
I have not 'coded' any SAS code yet. I am learning EG and it builds the code for you behind the scenes.
Under the filter tab of the query builder, you must associate your prompt(s) to column(s) within your dataset.
Here is an example of a basic filter with a single prompt:
Go to the filter tab, click the new filter icon
1. choose a basic filter, click next
2. select a column to filter on, click next
3a. select an operator (e.g. equal to, in a list, etc.)
3b.click the down arrow next to the Value text box, click the Prompts tab, select your prompt, click next
4. click finish
Run the query builder, and the prompt should present itself.