Problem with "Write-name-ds"

Please help with writing to an externally described file using a data
structure.
I have been to the archives, googled, RFMd (which appears to have some
inconsistent info concerning 'WRITE'),
and not found what I was looking for.

I am running at V5R2.

Situation:

I have 2 externally defined files with some common field names.
Common names are: Prt#, CYMD, and Cost.
I am reading/accumulating values from the first file and filling the
qualified DS fields before writing to the second.
At some point I have read a record, 'unqualified' field names contain
values from this record, and the 'qualified DS'
field names contain the values to be posted.

Problem:
I cannot figure out how to get the data structure written to the file
using the 
free-form "WRITE{(E)} name {data-structure}" method as shown in the
manual.

I realize I could do this other ways, "Prefix", another DS, etc., but I
like the concept of 'qualified data structure'
to differentiate fields, and really want to make this work, if possible.

*****************
Specifications for 'output' file:
FSrcCst    UF A E           K Disk
*****************
DDS for file SrcCst:
R SRCCSTR              
  PRT#          7S 0
  SOUR          2A
  CYMD  8S 0
  FOTG          8S 0
  COST            12S 4  
K PRT#
K SOUR
K CYMD
*****************
Data structure definition:
(PDM/SEU allows either of these)
D ScRecd        E DS    ExtName(SrcCst:SrcCstR:*Output) Inz
D                       Qualified
        ...or...
D ScRecd        E DS    ExtName(SrcCst:*Output) Inz
D                       Qualified

*****
(PDM/SEU does NOT allow these)
D ScRecd        E DS    LikeRec(SrcCst:SrcCstR:*Output) Inz
D                       Qualified
        The LIKEDS keyword is not valid with an externally-described
data structure.
        (What LIKEDS ????)

D ScRecd        E DS    LikeDS(SrcCst:SrcCstR:*Output) Inz
D                       Qualified
        The LIKEDS keyword is not valid with an externally-described
data structure.

D ScRecd          DS    LikeDS(SrcCst:SrcCstR:*Output) Inz
D                       Qualified
        A right parenthesis is expected but is not found.
        (To match with what ????)

D ScRecd          DS    LikeDS(SrcCst:*Output) Inz
D                       Qualified
        A right parenthesis is expected but is not found.
        (To match with what ????)
*****************
Compilation attempts and resulting errors:
040200  Write(E) SrcCstR ScRecd;
        *RNF7701 30        040200  Data structure SCRECD is not allowed
for the operation.

040300  Write(E) SrcCst ScRecd;
        *RNF5155 20        040300  The Result-Field operand is not
allowed for specified operation.
        *RNF5063 30        040300  Factor 2 operand must not be an
externally described file for this operation.
        From ILE RPG Reference manual for "Write":
                                                If name refers to an
externally-described file or a record format
                                                from an externally
described file, the data structure must be a
                                                data structure defined
with EXTNAME(...:*OUTPUT) or LIKEREC(...:*OUTPUT). 
                        ???????

040400  Write(E) SrcCst SrcCstR;
        *RNF5155 20        040300  The Result-Field operand is not
allowed for specified operation.
        *RNF5063 30        040300  Factor 2 operand must not be an
externally described file for this operation.

040500  Write(E) ScRecd;
        *RNF7260 30        040500  The Factor 2 operand is not valid for
the specified operation.

040600  Write(E) SrcCst;
        *RNF5063 30        040600  Factor 2 operand must not be an
externally described file for this operation.

040700  Write(E) SrcCstR;
        Compiles........ and in debug immediately before "Write(E)
SrcCstR;":
> EVAL screcd                
  SCRECD.PRT# = 0000010.
  SCRECD.SOUR = 'SI'
  SCRECD.CYMD = 20040401.
  SCRECD.FOTG = 00030039.
  SCRECD.COST = 00000001.3975

>EVAL Prt#
  PRT# = 0000010.               (value is from input file field Prt#)
>EVAL Sour
  SOUR = '  '                   (non-common field)
> EVAL cymd       
  CYMD = 20040202.              (value is from input file field CYMD)
> EVAL Fotg       
  FOTG = 00000000.              (non-common field)
> EVAL Cost           
  COST = 00000001.4116  (value is from input file field Cost)

File before "Write" had no records.
File after Write:
PRT#    = 10                    (correct, 'accidentally', from input
file)
SOUR    = '  '                  (incorrect, non-common, no SrcCst record
had been read to fill)
CYMD    = 20040202              (incorrect, from input file)
FOTG    = 0                     (incorrect, non-common, no SrcCst record
had been read to fill)
COST    = 14116                 (incorrect, from input file)

Thanks for any help or insight.

Tim Kredlo
Exterior Wood, Inc