Any possible transfer from Platinum to SoulSilver?

[Dossium]

Keeping it short:
Are there any possible ways to transfer Pokemon from my NO$GBA NDS .sav of a US Platinum ROM, to my more currently active NDS DraStic SoulSilver save?

Tons of time invested in both, and due to the Nintendo WiFi servers apparent shutdown, I am looking at options for keeping my teams alive.

[Exophase]

What you want to do is convert it to a dsv that's either a raw file or a DeSmuME save file. You can do the latter by using the import sav option in DeSmuME, then copy the .dsv file that it creates to sdcard/drastic/backup.

[TkSilver]

Keeping it short:
Are there any possible ways to transfer Pokemon from my NO$GBA NDS .sav of a US Platinum ROM, to my more currently active NDS DraStic SoulSilver save?

Currently the only way to do what you are looking to do is to own 2 nintendo DS systems and 1-2 flash carts (there are various ones that exist).
Import your DraStic save into DeSmuME

Import your saves from DeSuME to a physical DS.

If you are using flashcart, then just go to File -> Export Backup Memory and save the file on to the MicroSD card in the same folder as the rom. Make sure both file names match.

If you want to transfer it to a DS cartridge, then just go to File -> Export Backup Memory and save the file in a easy to access place. You need a flashcart or other simular device and use a homebrew application called Rudolph's Wifi backup tool that allows you to backup and replace sav files on you DS cartridges.

Make the trades you want and copy the saves back using DeSuME to convert if necessary.

[Exophase]

Sorry, I misread the question. Yes, this will require either physical DSes or some other emulator properly supporting local link in DS (don't know of any currently)

A less authentic option would be using a savegame editor or cheats to recreate the Pokemon, although I don't know if you'll have access to all of its stats. There could also be tools that can import and export Pokemon between save files.