assuming having a pageframe with 4 tabOrientation property(0,1,2,3),can solve this problem with many methods:

-make all pageframe pages(i).caption="" &&empty

1-method1
-add to form commandbuttons( support image+pictureposition and caption text)-use specialEffect=2
-place the commandbuttons exactly as pageframe tabs.(no need to make property pageframe.tabs=.f.)
-vertically can play with commandbutton.caption: add chr(13) after each character and you have it in vertically style as you asked.

2-method2
use labels instead (no image).can play with rotation property to set the pageframe.page.caption in any position between 0-360 degrees.
thisform.label1.rotation=65 && degrees or adjust it 0-360

3-method3
use images drawn as vertical style to replace the pageframe.page.caption

4-method4
use a class container with image+label grouping the previous methods

if you need a complet demo code , reply please.