Thanks both. I decided to go with Scott's suggestion, yielding more flexibility in displayed output:
copy /o C:\path1\* \\%NAS\path2\*.jpg > clip:
do asset in @clip:
iff %@index[%asset,=>] GT 0 then
copy /q %@word["=>",0,%asset] \\%NAS\path3\*.jpg
echo %@word["=> ",1,%asset]
elseiff...