How do I create an 3G2 file from an MP3 and a single JPEG?

I have been hand-rolling ringtones for my Samsung phone. It will let me use videos recorded on the phone as ringtones. It MUST be a 3G2 video, it MUST be in the DCIM folder on the memory card, and it MUST use the naming scheme that the phone uses to save videos. I have covered all these bases (see below) but when I use the phone's menues to select ringtones it displays the first frame of the video as an icon. Since there is no video, it displays a red X. I would like to add one image to the file, just to use as an icon. Following are the steps I currently use. This will give you an idea of the tools and skill level I have.

1) Create an audio file. (Usually that starts as an MP3, run through WinFF to convert to WAV, snip in Sound Recorder)

2) Use WinFF to convert the audio file to a video file using the preset for CDMA phone.

3) Normalize the 3G2 file to 92bD with MP3Gain.

4) Snap a short video with the phone.

5) Connect the phone to the computer using the USB cable and navigate to the DCIM folder.

6) Find the new video on the phone and rename the ringtone to that exact file name. The file name format is SPPX####.3g2.

7) copy the ringtone onto the phone. Confirm "Replace this file."