Embedded SQL Order By with host variables

I have a rather large SQL statement and I'm wondering about host variables
in the ORDER BY clause because I'd rather not copy it a number of times to
just order it differently.  I can't find any IBM documentation describing
using host variables to specify an ORDER BY clause, but the Precompiler
seems to allow it, and the query optimizer said something about host
variables in the order by clause being a reason that an ODP might not be
re-used.  I figured from this that it was permissible.  It seems to just
whatever entry is in the host variable.

Anybody here had success or seen something about this?

Thanks in advance.

simplified example:
______________________________________
Eval  SORT1='FAC'

/EXEC SQL
SELECT PROD, CLASS, FAC
FROM IMAST
ORDER BY PROD, :SORT1
/END-EXEC
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I've also tried:
Eval  SORT1=2

/EXEC SQL
SELECT PROD, CLASS, FAC
FROM IMAST
ORDER BY PROD, :SORT1
/END-EXEC
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