make RTF from input ASCII text file

makertf.bat

@echo off
set input="%~1"
set output="%~1.rtf"
::RTF header and font table (Courier New)
echo {\rtf1\ansi\deff0\nouicompat{\fonttbl{\f0\fnil\fcharset0 Courier New;}} > %output%
::page setup settings (landscape, legal, 0.5" margins)
echo \landscape   >> %output%

::Paper width and height and margins in "twips", or 20ths of a point, or 1/1440ths of an inch
::So legal paper (oriented in landscape) would be (14 inches * 1440 twips in an inch)=20160 twips long
echo \paperw20160   >> %output%
echo \paperh12240   >> %output%
::And a half-inch margin 
echo \margl720   >> %output%
echo \margr720   >> %output%
echo \margt720   >> %output%
echo \margb720   >> %output%

::F0 (only font in the table, Courier New) at 16 "half points" (8 point font)
echo \pard\f0\fs16\lang1033\par >> %output%

::Now read in the input file to the output file, adding \par after every line
for /F "tokens=* delims=" %%A in (%input%) do (echo %%A\par >> %output%)

::And we end the RTF with a closing curly brace
echo } >> %output%


::Open the file in the default editor
start "" %output%

RTF 1.9 official specification:
https://www.microsoft.com/en-us/download/details.aspx?id=10725