I want to trade my Mons for platinum to heart gold so I can play through platinum again. For me to trade them over, will I have to continue making constant runs back to the PC to switch my party out or is there any way I can access my PC while trading? And is it possible to transfer them all over at once using something like pokebank for example?
The actual trading interface remained largely the same throughout the series's first four generations: Each player selects one Pokémon from their party to offer for trade; once decided, they can review the stats (and, when applicable, Ability or item) of the other Pokémon before confirming or cancelling the trade. The player may perform multiple trades in a row. It is not possible to trade Pokémon stored in the PC in these generations, so they must be placed in the party prior to speaking with the receptionist at a Pokémon Center.
source There are no (legitimate) third party tools that can trade Pokemon in a PC in HGSS, as My Pokemon Ranch is compatible only with DPPt. source So no. sorry.
