How to manage different and shared contents ?

[eluser]Berik[/eluser]
Hi there,

I have to work on a french website that covers 4 different departments (department would translate to "state" in the USA). The particularity of the site is having some pages identical to the 4 departments and others that have different contents based on the locations.

Ideally I'd like to set it up with virtual subdomains :

www.example.com -> root where users select their department
dep1.example.com -> 1st department
dep2.example.com -> 2nd department
dep3.example.com -> 3rd department
dep4.example.com -> 4th department

I believe this can be done with htaccess, would that be true ?

next up :
each homepage is slightly different contents-wise but the about page is the same for all 4.

How would you do this ?
I'm thinking of using custom routes and using the backrefences to conditionaly load the corresponding view but am not sure if that would be the best way.

Thanks for you help

[eluser]Berik[/eluser]
Still looking for feedback

[eluser]Berik[/eluser]
Commenting on my own post

It seems that SEO is more relevant when using sub folders rather than sub domains (well that's what I've found out while searching the question on the web anyway)... So I'll go the sub folder route instead.

Although I'm still curious about my initial question