Unable to utilize a field resulting from CAST sub-query

Question

1. Summarize the problem: I need to capture the result of the CAST sub-query. When executing both SELECT statements only, the query is successful and I can see the returned value in DT_CONV (2022-03-17).
   However, when I attempt to utilize DT_CONV or current_date_yyyy_mm_dd_conv, in a lower part of the query, the system does to recognize it.

   Syntax error: Expected end of input but got identifier "DT_CONV" at [1:1] Unrecognized name: current_date_yyyy_mm_dd at [24:82]

2. Describe what you’ve tried: Looked at many, many syntax examples

3. When appropriate, show some code: SELECT (SELECT CAST(CURRENT_DATE() AS STRING) AS current_date_yyyy_mm_dd_conv) AS DT_CONV , Office_Location , Pole_NBR etc......

Thanks!