If you know format of file then you could write your own program - something like:
strings /dev/vx/dsk/testdg/testvol | awk '
/start_pattern/ {n+=1;filename="/recover/file"n;want=1}
want ==1 {print $0 > filename }
/end_pattern/ {want=0}'
Maybe able to get filename also with a bit more intelligence.
But make sure you recover files to a different filesystem and note if files are fragmented then this won't work well and you will probably also get incomplete files from parts of files that have been overwritten.
Mike