Sounds like you're on a complete hospital pass, as they call it in rugby.
So they want 100 columns and how many rows?
Then they want to analyse it?
I've not reported against BW for five years, so probably not the best person to advise you but I'd be looking at what hierarchies there are for drilling, looking at report filters, input controls and things like that. That said, if you can't get the data out with a single Bex query then there's a bigger issue than how to present it.
The key, as I said, is finding out what they want to do with the data - Webi is no ETL tool but it does ad hoc analysis very well.