I remember way back to like idk around 2000 - 2002, there was a live action kids show that was on saturdays and it was right after Sonic Underground then after the live action show it was Sabrina the animated series....
I can't remember the name of the show or the kid's name but it was like a high schooler boy i think brown hair and he was chased by these monsters you'd see in a video game like ogres and a wizard and these flying eye balls all i know is that they came to his world looking for something and that's about it
1999 as Sabrina and Sonic Underground were 1999 s to have it in between the 2 must mean it's the same year.
I don't have a clue what that is though since it's live action kids 1999 rather than cartoons as my list for 1999 isn't combined it's cartoons only unfortunately so the only things I can remember now are the live action kids I grown up on and the later night TV I watch now sorry.
But at least you'll know where to possiblely go trecking now any list with 1999 live action kids shows may have what you want unless it really was 2000.