The good news is that you don't have to catch all the Pokemon, but you only have to see all the sinnoh Pokemon to get the national dex:)
no there is not i have checked extensively with no good results.
There is a cheat from Action Replay that gives you all Pokemon on the National Dex
Capture all the Pokemon On the National Dex.
Regional dex-unown. National dex-tangela.
pichu in Sinnoh Dex exeggutor in National Dex
the Pokemon for national dex number 124 is jynx and for sinnoh dex number 124 the Pokemon is azurill.
this site has a complete diamond/pearl walkthrough, info on every Pokemon in the national dex and where to get them all and how to evolve them, and other great stuff! check it out! www.Pokemon.marriland.com
Pal park, migrating from Ruby/Sapphire/Emerald after obtaining national dex
complete the pokedex then go to professor rowan and he will give you the national dex
first you need to get the national dex to do this you need to see all Pokemon in sinnoh to compleat the national dex see all Pokemon on the poke dex
goldeen (or rapidash on the national dex)
yes when you get the national dex