well, i just ask can we use emulator like no$gba to play vnds?

what that is a terrible idea why would you want to do that.

As far as I know, yes you could do it but it'd be terribly impractical.

Also to quote #2
"Why would you want to do that?"
It's not like these games don't already exist in a PC form... you could play those far easier than you could use an emulator.

Hm, I can think of two reason's already:

one - he may not have access to the orignal game, and If he's planning to 'aquire' it, the ds port would most likely be 10x smaller

two - If He's creating/porting his own, It might be easier in the testing phase to use an emulater, to same the 'swap out card' routine (I use the old school way, be others might be different)

And yes, you need to get a copy of the souce code (available at the same play you download the non-source VNDS). With that, there are instructions on what you need to do (from memory, you change a line in a file, and compile it) then you can do it