Took a shot at it...

SELECT

PARSENAME(REPLACE([Subject],';','.'),1) AS Subject1,

PARSENAME(REPLACE([Subject],';','.'),2) AS Subject2,

PARSENAME(REPLACE([Subject],';','.'),3) AS Subject3

FROM YourTable

Works with your sample data and the assumption that 3 subjects is all you'll need. If the number of subjects changes, tweaking will be necessary, but this should do for the moment.

EDIT: Gah, that's what I get for being interrupted while I'm thinking :hehe:. This reverses the order of the original input. One moment while I correct that...