Nope, they are completely different. Special roast can be described as a "super biscuit," which even in small amounts lends a biscuity-toasted flavor. In larger amounts it can be very bready and tart, nearing that of bread dough.
Regardless, if you want to use brown malt, you really need to buy the real stuff. Thomas Fawcett makes what most consider the best and most authentic brown malt, it is around 65+L and provides those lightly roasty coffee/chocolate flavors. There is no substitution.