you cannot
You can get ditto in route 218 by using a pokeradar i think?
you need oak's letter and then you have to go to route 224 in pok'mon diamond, or pearl. I am not sure about poke'mon platinum
You can obtain Swinub from the swarm in Route 217 in Pokemon Pearl.
You can get a Seel in Pokemon Pearl by finding it in the water on route 226.
Route 241 does not exist in Pokemon Pearl it only goes upto Route 230
all the Pokemon on route 210 in Pokemon diamond and pearl are ponyta, geodude and if your really lucky you can find onix.
Route 114 doesn't exist in Pokemon Pearl, however, there is a Route 214, which is in between Veilstone City and the Hotel Grand Lake.
Route 225 is not a route that can be found in Pokemon Firered, route 225 is in Pokemon Diamond, Pearl, and Platinum. To get there is Diamond Pearl and Platinum, you have to see every Pokemon in Sinnoh, then talk to Prof. Rowan and get the national dex.
Wayward Cave
In Pokemon Diamond and Pearl, Phanpy swarms on Route 207.
on route 212!
In route 201