First, downloading karaoke songs over the internet is illegal unless you purchased them.
I assume these are in MP3+G format. This format actually has 2 files per song; a .mp3 music file and the .cdg file with the graphic lyric data. This is NOT the same CDG format that Microstudio writes to a CDG disc. That's most likely your problem. You need a program to convert the .mp3 and .cdg files to a true .cdg file, identical to what is stored on a CDG disc.
Maybe someone else can help you with this. We don't deal in MP3 software, or illegal downloads.
I strongly suggest you abandon using illegal files. If you are an individual, you may get away with it. If you are making a living with this, you will one day be discovered and loose all your computers, audio gear, and possibly even your car/van you transport the "illegal" files with.
If I'm reading something else into your posts (aka internet downloaded karaoke), then forgive me. More details overcome assumptions.
