Configuring .htaccess for multiple wordpress sites - wordpress

Question

I have multiple wordpress installs that I need to access with multiple domains and I need a way to accomplish this. I have devised a folder structure that I think will be the best way, but I need help with the .htaccess. For simplicity sake, let's say I have two wordpress sites. Fully separate.
www.b.campscoreboard.net is in the folder
/a/b
www.c.campscoreboard.net is in the folder
/a/c
www.campscoreboard.net is pointing to
/a
The a folder contains nothing except an .htaccess file to help me route the domains properly. That's where I need help. I would like to point www.campscoreboard.net to that root /a folder. In my perfect world, the following things would work.
The "b" site would work just fine using www.b.campscoreboard.net or campscoreboard.net/b
The "c" site would work just fine using www.c.campscoreboard.net or www.campscoreboard.net/c
I need "b" and "c" to have their built in permalinks functions to still work. In other words, if I type www.c.campscoreboard.net/forums, I need that to work. I don't want to have to go all the way back to www..campscoreboard.net/c/forums for my links to work (which is what it's currently doing).
What needs to be in that .htaccess file in the /afolder to properly route these domains?
Update 1: Rather than breaking real sites trying this stuff, I just made 2 wordpress installs in the directory tree above. Sorry about the www's. That's what worked for testing purposes.
Here's what happened:
After installing the sites, they worked as expected. I could load the two wordpress sites with either b.campscoreboard.net or campscoreboard.net/b.
However, I got an internal server error on all campscoreboard.net, b.campscoreboard.net, and c.campscoreboard.net after adding the suggested .htaccess of...
<VirtualHost *:80>
ServerAdmin admin#localhost
ServerName b.campscoreboard.net
ServerAlias www.b.campscoreboard.net
DocumentRoot /a/b
ErrorLog ${APACHE_LOG_DIR}/error.log
CustomLog ${APACHE_LOG_DIR}/access.log combined
</VirtualHost>
<VirtualHost *:80>
ServerAdmin admin#localhost
ServerName c.campscoreboard.net
ServerAlias www.c.campscoreboard.net
DocumentRoot /a/c
ErrorLog ${APACHE_LOG_DIR}/error.log
CustomLog ${APACHE_LOG_DIR}/access.log combined
</VirtualHost>
What do you think I'm doing wrong?

Answer 1

Follow these steps:
a) Create Apache virtualhost:
Read this tutorial.
Example configuration:
<VirtualHost *:80>
ServerAdmin admin#localhost
ServerName mudministry.com
ServerAlias www.mudministry.com
DocumentRoot /mudmin/home
ErrorLog ${APACHE_LOG_DIR}/error.log
CustomLog ${APACHE_LOG_DIR}/access.log combined
</VirtualHost>
<VirtualHost *:80>
ServerAdmin admin#localhost
ServerName userspice.com
ServerAlias www.userspice.com
DocumentRoot /mudmin/userspice
ErrorLog ${APACHE_LOG_DIR}/error.log
CustomLog ${APACHE_LOG_DIR}/access.log combined
</VirtualHost>
b) Add wordpress files in /mudmin/home and /mudmin/userspice. Make sure you access these sites first time using the servernames specified above. mudministry.com and userspice.com
This will make sure the your wordpress urls are generated correctly.
c) Use Reverse proxy for mudministry.org
Read this tutorial:
Example configuration:
<VirtualHost 10.10.1.91:80>
ServerName mudministry.org
ServerAdmin webmaster#localhost
## You dont have to keep this /mudministry
DocumentRoot /var/www/
ErrorLog ${APACHE_LOG_DIR}/error.log
CustomLog ${APACHE_LOG_DIR}/access.log combined
ProxyAddHeaders Off
ProxyPass /home http://mudministry.com
ProxyPassReverse /home http://mudministry.com
ProxyPass /userspice http://userspice.com
ProxyPassReverse /userspice http://userspice.com
</VirtualHost>