I wouldn't say it's impossible.
You could dump the R4's firmware, reverse engineer and hack it, then flash the R4 with your modified firmware.
Its just really difficult. =P
It wouldn't be that difficult... You wouldn't need to dump the firmware, you should just use the loader. You could decrypt it using R4crypt or a similar tool. You'd modify it and recrypt it. Then you'd rename it to _DS_MENU.DAT and put it on your SD card.
It's still hard, but it's a lot easier then what you propose
I don't think it'd even work. If you could program it like that, it'd still be impossible to flash the R4 AFAIK. If that's not the case a update for SDHC-compatibly would be possible too
what is this guy asking?
does he mean to go straight to the games when the R4 boots?
why the hell would you want that?