Add a text/sentence inside a PDF

Question

I need to take a big pdf document and goto certain pages and locations and add some comments there for the section number.
I tried to do this by first adding text boxes in those regions and then i dynamically opened it with my program and put the value in them.
However the issue is that each line added can only start from a new line.
But i want to add the text inside a paragraph or at the end or start, it should flow from middle of one line to the middle of another.
I dont want it looking different, inside a text box, but rather look normal like part of the text.
Please let me know how i can do this, i looked at the samples and examples but could not find an example to help add text inside a paragraph of a pdf.
thanks

Answer 1

Then how do i accomplish this task, let us say below is the para on the acrobat file
Colestrol will accelerate heart disease risk by promoting fatty
deposits and inflammation in the arteries of the heart. Reduction
of excess body fat slows this process. Your Body Mass Index
indicates [<moderate obesity>] and it is a must [<that you lose
weight and increase exercise>] to reduce your risk of heart disease.
To accomplish this task, we are inserting two variables shown as [<bold>]
There are two issues here:-
1) [<moderate obesity>] - if this is a short word like "normal", then there will be white space at the end of the line.
2) [<that...exercise>] - this starts in the middle of a line and ends in the middle of the next line.
My guess is i need to add the variable string to the rest of the para at run time and set the whole para dynamically in one shot.
So the whole para would be comming in from the server side code.