There is a program called TMPGEnc that will convert just about any video file you have a codec for to a VCD compliant mpg that can be burned directly to a VCD using Nero. You can google for it.
An NTSC VCD has the following specs
mpeg 1 stream type
352x240 resolution
29.97 frames per second
4:3 525 line Aspect ration
Audio sampe rate of 44100hz
Stereo sound
I usually set the audio bit rate to 224 kbits/second
A PAL VCD is basically the same with the following diffences
352x288 resolution
25 frames per second
625 line aspect ratio
Also there is a System tab, make sure it says Mpeg-1 Video CD
The program is really simple to use. Browse for the video source, if the video has audio you don't have to worry about browsing for an audio source but, I have been able to merge bmps with wavs into an mpeg that plays music and displays a picture. After you load your video click the settings button and configure it like i showed you above and then click start. It'll take a few hours to convert.
Both formats also have a 16:9 aspect ratio you can choose as long as you keep 525 lines for NTSC and 625 for PAL. To be honest I'm not sure which format Puetro Rico uses. I'm assuming since you're close to the USA that it will be NTSC but I could be wrong. But, if you have the right DVD player it really doesn't matter. Mine will play either on my NTSC TV. I've burned many disks in PAL format simply because it's the way I downloaded the file and so it did not need any converting to become a VCD.
A second option, which i do not prefer, is to allow Nero to do all the converting for you. I don't prefer this method because you can not preview the quality of the mpeg before it becomes a VCD and the disk may end up funky looking.