The print action field in the dt configuration files should be modified to add the Hebrew text filter. For example, in the dtmail application, the print action in the file /usr/dt/appconfig/types/he/dtmail.dt should be:
ACTION Print
{
LABEL Print
ARG_TYPE DTMAIL_FILE
TYPE COMMAND
WINDOW_TYPE NO_STDIO
EXEC_STRING sh -c ' \
dtmailpr -p -f %(File)Arg_1% |
/usr/lib/lp/postscript/convert_text -inputTextMode
-text_mode_implicit -outputTextMode text_mode_visual
-lineWidth 80 -inputLayoutDirection left_down
-outputLayoutDirection right_down| mp -A4 -L he| dtlp
-u %(File)Arg_1%;'}
The listed convert_text parameters will print right-aligned text right-to-left. To print text aligned to left, left-to-right replace the previous parameters with -lineWidth 80.