There are several missions that have a Swiss Bank account requirement. So it is very likely that you will obtain this one over the course of playing said missions. The easiest mission by far is where you need to get 75K in your account before 1990.
Just make sure to do the following:
* As soon as you start the game press RT+A and select the building permit edict. This will cost you $500 but from now on 10% of a buildings cost goes to your swiss bank account!
* Have you seen that cigar factory, oil drill and furniture factory? At certain points in time the game will ask you to make a choice. You get two opportunities to increase your swiss bank account balance with $5000.
* Build up your economy by constructing an iron mine right above your palace and several tobacco farms below your palace. From there on out just keep upgrading and building everything making sure everyone is at least moderately happy.As soon as you build a bank, select it and make sure it siphons money to your swiss bank account. Per year it takes ~10% of your current in game balance and transfers it to your swiss bank account!
Don't forget that there are two places you can build an oil refinery! Those will net you some serious cash!
* If you're still not stealing enough from the people Prez, might I suggest you build more Cathedrals? They are 20K a piece and thus up your swiss bank account by $2000. Whenever a new one is build just destroy it, and build another one (or two or three...)
I managed to build up a pension fund of over 120K by 1989.
There is no need to do this during the mission! You can get the achievement(s) when you continue playing after you've won or in a sandbox game (just make sure god mode is OFF).
If you have any questions feel free to PM me or add me on Live.