Answer
You'd have to find a forex dealer that carries the exotic currency/currencies you have in mind. MigFX carries a number of exotics (www.migfx.com). What you have to be concerned with is the PIP spread. For example, on the EUR/USD pair, the PIP spread is 3.5. But on the exotics, the PIP spread can be quite high. On the NZD/SEK (N Zealand Dollar/Swedish Krona), there is a 75 PIP spread and on the USD/ZAR (Dollar/S African Rand) there is a 150 PIP spread, these were taken from MigFX.