how to use unzipsfx to extract files to desired directory?

Hi guys,
I've been searching and searching and all the web gives me is the man page for unzipsfx. How do i use the '-d' command to have my self-extract EXE file extract the files to a desired directory?

The man pages gives me this:
To create a self-extracting archive letters from a regular zipfile letters.zip and change the new archive's permissions to be world-executable under Unix:

cat unzipsfx letters.zip > letters
chmod 755 letters
zip -A letters

now, how can i configure the self-extract zip file extract the files to a hypothetical directory of ./testscript when i run the file 'letters'? Thanks for your help.

i guess to summarize, how do i convert the following DOS batch file syntax...

wzipse32 %2 -d C:\%2 -y
where %1 is the desired extracted destination directory,

.... to UNIX shell scripting?