We have no idea here in the One For All forum. So you probably need to post in one of the Pronto forums.

However, generally there are 2 types of protocols common with samsung, one of which repeats when held and another that doesn't. So try the codes from different models until you find the repeating version. If you find some pronto hex on this site for the volume commands, the NEXx1 or NECx2 versions should do the trick.