Just create a seperate .cfg file for each device you want to collect data from. Then have a main page you designed to link to each devices index.html from the .cfg you specified.
IE: I have 6 clients I collect data from.
I thus have 6 different .cfg files under /etc/mrtg/clients/
I run indexmaker 6 different times and run my collection scripts every minutes through cron.
Then I have 1 web page using a virtual server within Apache to specify
http://<hostname>/mrtg2/index.html
I created the index.html with links to each of my devices seperate index.html
Make sense?