[PeterT]

In theory yes.

From http://www.pokezam.com/forums/showthread.php?t=3924

Vbulletin Admin CP Interface
How to Get There

1. Go to your admincp (/admincp/) and login.
2. Look for "Custom BB Code" on the left menu. Its near the bottom.
3. Expand it and click "Add New BBCode".

Superscript
Title: Superscript
Tag: sup
Replacement: ^{param}
Example: 2[sup]2[sup]2[/sup][/sup]
Description: Makes text superscripted, such as with mathematical exponents.
Use Option: No
Remove Tag if Empty: Yes
Disable BB Code within this BB Code: No
Disable Smilies within this BB Code: No
Disable Word Wrap within this BB Code: No

Subscript
Title: Subscript
Tag: sub
Replacement: _{param}
Example: 2[sub]2[sub]2[/sub][/sub]
Description: Makes text subscripted.
Use Option: No
Remove Tag if Empty: Yes
Disable BB Code within this BB Code: No
Disable Smilies within this BB Code: No
Disable Word Wrap within this BB Code: No