MOD REWRITE (BASE) on WAMP Server - apache

Question

I have an WAMP webserver with Rewrite module activated.
I have all my projects in:
d:/prj/costumer1/www/ (alias: costumer1)
d:/prj/costumer2/www/ (alias: costumer2)
and so on...
For costumer1 I have an .htaccess-file that works just fine. Looking like this:
RewriteEngine on
RewriteBase /costumer1/
RewriteRule ^([^/\.]+)/?$ index.php?a=$1 [QSA]
RewriteRule ^([^/\.]+)/?/([[a-zA-Z0-9_-]+)$ index.php?a=$1&b=$2 [QSA]
RewriteRule ^([^/\.]+)/?/([[a-zA-Z0-9_-]+)/?/([[a-zA-Z0-9_-]+)$ index.php?a=$1&b=$2&c=$3 [QSA]
Now when I create a src/href-link I now have to use:
/costumer1/search/book/novell (aka: costumer1/?a=search&b=book&c=novell)
instead of
/search/book/novell (aka: costumer1/?a=search&b=book&c=novell)
So in short:
I don't want to write "/costumer1" in front of every link: search

Answer 1

I have done something like this in my root .htaccess
RewriteCond %{HTTP_HOST} ^customer1$ [NC]
RewriteCond %{REQUEST_URI} !^/customer1
RewriteRule ^(.*)$ customer1/$1 [L,NS]
But eventually, I moved away from handling this with .htaccess as it was less scalable, and went on to setting virtual hosts, something like this:
<VirtualHost *:80>
DocumentRoot "D:/htdocs/customer1"
ServerName customer1
</VirtualHost>
<VirtualHost *:80>
DocumentRoot "D:/htdocs/customer2"
ServerName customer2
</VirtualHost>
And for this to work, of course edit your hosts file, to have lines like this:
127.0.0.1 customer1
127.0.0.1 customer2