Please don't use private messages to ask for help. Use the public forums. If you search for awk book or sed book you will find that your question has been asked and answered many times before.
If you collapsed the awk script I supplied to a single line (without adding some semicolons), I'm very surprised that it still worked at all. I don't see any difference in the above two output segments. If you mean that you want the <newline> characters separating lines in the replacement text file to be included in the output, you won't have a valid CSV file unless you quote the <newline>s. With the input files I used before, and the following code:

Code:

/usr/xpg4/bin/awk -v r=2 -v c=3 '
BEGIN {	FS = OFS = ","
}
FNR == NR {
	val = sprintf("%s%s%s", val, NR > 1 ? "\n" : "", $0)
	next
}
FNR == r {
	$c = "\"" val "\""
}
1' rep csv

the output produced is:

Code:

1.1,1.2,1.3,1.4,1.5
2.1,2.2,"this is a two-line
replacement file",2.4,2.5
3.1,3.2,3.3,3.4,3.5

Is this what you wanted?

In the future, please supply sample input and sample output so we can see what you're trying to do.