lily,

Try the following e.g. for A1 split into B1,C1,D1.
In B1....
=TRIM(LEFT(SUBSTITUTE(A1," ",REPT(" ","99"),31-LEN(SUBSTITUTE(LEFT(A1,31)," ",""))),99))

In C1....
=TRIM(LEFT(SUBSTITUTE(SUBSTITUTE(A1,B1,"",1)," ",REPT(" ","99"),31-LEN(SUBSTITUTE(LEFT(SUBSTITUTE(A1,B1,"",1),31)," ",""))),99))

In D1.....
=TRIM(SUBSTITUTE(TRIM(SUBSTITUTE(A1,B1,"",1)),C1," ",1))

Should give max 30 characters per first two cells and then the balance in third cell. The split will depend upon the occurrence of spaces / the length of words at or around the split points. If text in A1 is close to 90 characters and the words on the split points are long then you could find that the balance of characters left to go in D is greater than 30????

Try it on your real data and see how it goes.

Once split out by the formulas if you wish, you can convert the results to 'hard' text by doing a Copy >> Paste Special >> Paste Values in situ.