Hi.
TextStar or TestStar (you mentioned both) doesn't ring a bell to me.
Is that a type or a brand ?
In case it is a brand, then what type are you talking about ?
Do you have a picture, and can you show that (or a link to it).
An Arduino has a TTL level RS232 port, and just RX and TX.
Handshaking and such stuff aren't there (initially i typed "are missing", but who misses those ?).
This has a very simple reason:
You only need a standard port which can also be used for other purposes, ad you will save a dedicated port with some additional level shifting hardware.
So if you need a real RS232 port, you'd have to add that piece of hardware yourself.
That would be a MAX232 (or some derivate) and supporting components, of which some 4 capacitors (acting as charge pumps) are the most important ones.
Google MAX232 for 5 volt level or MAX2323 for 3 volt level, you'll find lots of information.