Newbie: connecting to MS SQL 2008 R2 from MacOS 10.5 running XAMP

Hello folks,

I've spent the last two days familiarizing myself with the documentation and
steps for installing freetds. The good news is that the documentation on the
website has been helpful and I was able to download the source, build the
executables, and test the connection using tsql. Currently, my installation
is located in the default directory */usr/local/freetds* and my conf file
with sql server information is located in */usr/local/freetds/etc*, but now
I am confused how am I supposed to tell XAMP, which is located in
/Applications/XAMP to use freetds?

My XAMP installation has a freetds.conf file located in
/Applications/XAMP/xampfiles/etc

One more thing... when I did some google searches I found some threads that
discussed a mssql.so module which I am supposed to put into my php.ini file.
My php.ini file is located in /Applications/XAMP/xampfiles/etc, but I
believe the mssql.so is for something else not related to freetds, am I
correct? If so, what are the major differences between mssql.so and freetds?

Thanks for all of your wonderful help!