Best way to mass-mail a dynamic segmented 7500-email list

Hi and please accept my apologies if I am posting in the wrong section, I really couldn't understand if I should post in some other particular place.

I have a customer that wants a way to mass-email his list of contacts.

He has that list in Excel and has
- three languages
- 15 sub groups per language (main, VIP, etc)

From all I have been researching, I couldn't find any hosted solution that could accomodate this easily. Although I have learnt about the "segments" solution many provide, the problem is that these segments are not dynamic.

So, if I add new stuff to the main list, I will have to recreate each and every segment (except if I keep track of what is added and skip recreation of the unnecessary segments, but even that is too cumbersome and time-wasting).

I would really like to use a hosted solution like e.g. VerticalResponse or GetResponse but they would have to accomodate this need (it's really impractical to setup a system that would need so much manual work for 45 segments!)

If nobody knows of a way to do this with a hosted solution, then what do you suggest I use for a Windows setup? In this situation, my ideal scenario would be a software that could connect to an Excel file (without needing to import it), and select the conditions for the segmentation in realtime (e.g. Language=English AND Group=VIP)

Thanks for all the help you can give me, and all the best.

LC