Anyone can help with this?

Drop - Down Box - Finance, Accouting, etc. (5 others)

Expenses:
Relocation, Recruiting, etc. (list has 30 items)
Now, I am forecasting so they will put these expenses for 12 months for each
expense for each department. Therefore, if I create multiple drop down lists,
I still have the same problem, because it is the same expense types for each,
however, the amounts will all vary depending on department. I can not create
multiple lists because it is too much stuff. Any ideas on how I can do this?
Thanks.