The Raytrace 3D renderer uses a brute-force method and thus renders every frame. Your only option would be to pre-render image sequences and use those.
If I understand you correctly all you need to do is render a single frame of whatever the image is you need. Maybe the entire image or just the text with transparency? Probably better to do just the extruded text with transparency as you will still have the option of changing whatever is behind it or on top of it. Just move to a frame where the animation has stopped then menu to Composition>Save Frame As> File. Bring the rendered still back in and insert it between where the animation stops and starts using in and out points of the relevant layers. If there is no movement happening I don't think you need an image sequence. Just the single frame
Thanks for fast answer, this is what I wanted to know.
Thanks, yes, I did it.
I just wanted to know if it's possible to... no, it isn't.