Hello, I would like to know how to accomplish this:

I have a worksheet with single cells (in the A column), each with the same
layout of info inside, separated by semi-colons (they actually originate
from .csv files) I want that info to be separated from each cell into
multiple (I.e. to have info not altogether in column A but in multiple
comumns) automatically, and also, because more similar cells are added
regularly to that A column, I want that process to also update with the
latest added info every time.
For example I have cells like this:

Notes; 0001; "Economics"; "you should..."
Notes; 0002; "Literature"; "Hamlet tried..."
....
Scraps; 0040; "The Three Musketeers"; "Athos picked an..."
....

and I want this:

Category Number Subject Message
Notes 0001 Economics you should...
Notes 0002 Literature Hamlet
....etc....

I tried using combinations of formulas like LEFT, MID and SEARCH, and it
kinda worked for the cells that the formulas were referring to, however I
found no way to have new cells added and updated when I added new similarly
mingled cells. I also tried to select the first 4 columns and copy the
formulas to all cells, but that caused the file to require half an hour to
open, get saved and manipulate in general.....perhaps a macro is the way to
go? but how, I have no knowledge of VBA.

Thanks in advance for your help!