eLaTeX presents an interesting idea to controll directionality of paragraphs, 
and in-paragraph words. 
It offers two types of of "Directionality parenthesis" \L{} and \R{} which 
denoted L2R and R2L directionality respectively. Shortly, one writes a 
paragraph, whose main directionality is determined in the head of the 
paragraph (by \sethebrew and \unsethebrew BTW) and in-paragraph english 
sentences are written inside a \L{} parenthesis. 
EXAMPLE: 
HEBREW PRAGRAPH TEXT \L{some english 123} 
obviously it works the other way around, with English paragraph using \R for 
in-paragraph hebrew sentences, thus, numbers and punctuations' directionality 
can be determined. 
 
As using LaTeX notation in a WYSIWYG editor, I suggest we'll implement an 
"English/Hebrew Box" feature. That is when English text is written in the 
middle of R2L hebrew paragraph, a sign denoting the beginning of an 
in-paragraph English sentence will be shown before this wordand a special key 
will allow the user to end the English section whenever he desires. The text 
inside the "English box" will be rendered as if it is a L2R text and 
punctuations' font will be Latin. 
 
Obviously similar thing will happen to Hebrew text in an English L2R 
paragraph. 
 
PLEASE NOTE: this will save as the trouble of using character-types, also it 
will save as the trouble of implementing IME recognition algorithm.