replacing text in files w/ a script

Hi.  I working in Windows using Cygwin, a UNIX emulator.

I'm trying to do what I did in UNIX a lot, replace text phrases in files in the current directory and all subdirectories.   I have Cygwin, but can't get the syntax correct.  If there is a better shell or a better way, I'd like to know that too .

I like emacs, so ideally I'd do this in an emacs shell on Windows XP.

the sed command I'd use has the form:

sed 's/\/lt\//\/lt4\//g' * > ????                           ;replace "/lt/" with "/lt4/"  and do this with files in all subdirectories too

So, for each file found it should make that replacement and put it back in the same file name.  I also tried to break it up into a sed file and a find command:

find . -name "trial.*" -exec sedscript.sh {} \;

and I got this output:
[begin output]
starting
export: =: bad variable name
File = ./trial.cpp
export: =: bad variable name
cp missing file operand
Try cp <snip>
sedscript.sh: cannot create : directory nonexistant
rm missing operand
[end output]

my sedscript.sh file looks like this:

echo "starting"
export FILE = $1
echo "File = " $1
export TMPIN = "$FILE".tmp
cp $FILE $TMPIN
sed -e 's/\/lt\//\/lt4\//g' $TMPIN > $FILE
rm $TMPIN

so, I'm pretty much getting an error on every line.  Ideas?  Thanks!
Gene