How do I INCLUDE html from a file

Hi,

Just wondering if there was a way to include a file in a WIDGET. I basically want to create a small list in HTML of the different subdomains I have because each is a different topic. I envisage creating perhaps 1 or 2 topics per week and then would add to my table and upload that file to the main domain. Each subdomain has a blog and I would like each blog to be able to display the latest list of conents as held in the uploaded file.

It’s a bit like an INCLUDE statement in php but that doesn’t work in the TEXT Widget.

Any other suggestions greatfully received