This is not my knowledge, but the information that i got from others when i posted a thread in the C+C forum titled 'Leaderhead creation for dummies'.
I'm posting it here because i think it will be helpful as a reference to others who want to create leaderheads using this program.
I will state the names of the people who provided the information at the top of thier text.
I'm sure the lads won't mind.
NAME: Kinboat:
I recently finished several leaderheads made with Poser 4 (and PSP7), so I guess I could help out here a little (although there are others with more knowledge and talent).
1: First change the size of your view window to 400x480.
2: Next add your model and position it within the frame.
3: Open the animation palette under the 'windows' menu and make your animation 121 frames long (at the top right).
4: You can exit out of that window and go back to the main screen, at the bottom there should be an animation tool bar that lets you play, pause, frame advance etc. Drag the bar to frame 61 and create the Neutral expression on your model.
5: Drag it back to frame 1 and create the Happy expression, then go to the end (121) and create the Mad expression.
6: Obviously that's just the simplest way, Poser will transition between the three Key frames and create the general animation. You can go into much more detail... For instance to get the blink effect that the original games Leaderheads have:
Start a blink at frame 19 Full blink at 21 and End at frame 23...
Again at 39 - 41 - 43... 99 - 101 - 103... and 109 - 111 - 113.
Now the guy should blink occasionally in the game.
7: Now once you have the animation done go up to the Animation menu and select make movie... Make and AVI movie using 'Current Render Settings' and selecting 'Half' size. In Sween32's advice to me he mentions it'll take between 20 minutes to 4 hours to make the movie... Most of mine are from 1 to 4 hours, tending to the long end of the scale. Once that's done open the file in Jasc Animation Shop (comes with PSP7, a similar program will probably work but I don't know )
I'm posting it here because i think it will be helpful as a reference to others who want to create leaderheads using this program.
I will state the names of the people who provided the information at the top of thier text.
I'm sure the lads won't mind.

NAME: Kinboat:
I recently finished several leaderheads made with Poser 4 (and PSP7), so I guess I could help out here a little (although there are others with more knowledge and talent).
1: First change the size of your view window to 400x480.
2: Next add your model and position it within the frame.
3: Open the animation palette under the 'windows' menu and make your animation 121 frames long (at the top right).
4: You can exit out of that window and go back to the main screen, at the bottom there should be an animation tool bar that lets you play, pause, frame advance etc. Drag the bar to frame 61 and create the Neutral expression on your model.
5: Drag it back to frame 1 and create the Happy expression, then go to the end (121) and create the Mad expression.
6: Obviously that's just the simplest way, Poser will transition between the three Key frames and create the general animation. You can go into much more detail... For instance to get the blink effect that the original games Leaderheads have:
Start a blink at frame 19 Full blink at 21 and End at frame 23...
Again at 39 - 41 - 43... 99 - 101 - 103... and 109 - 111 - 113.
Now the guy should blink occasionally in the game.
7: Now once you have the animation done go up to the Animation menu and select make movie... Make and AVI movie using 'Current Render Settings' and selecting 'Half' size. In Sween32's advice to me he mentions it'll take between 20 minutes to 4 hours to make the movie... Most of mine are from 1 to 4 hours, tending to the long end of the scale. Once that's done open the file in Jasc Animation Shop (comes with PSP7, a similar program will probably work but I don't know )