I need excel 2007 to perform a minor miracle!

Here's the problem:


A B C D
E
1 Number Procedure Date Procedure repeated? Days between
2 procs
2 123 RCA; LAD 01/01/08 Yes
521
3 213 LAD 02/01/08 Yes
631
4 314 RCA; Cx 02/02/08 No
637
5 489 RCA; Cx 03/04/08 Yes
535
6 213 Cx 02/01/09 No
302
7 512 LMS; graft 04/04/09 No
210
8 123 RCA; Cx 05/06/09 No
148
9 489 Cx 20/09/09 Yes
33
10 213 LAD 24/09/09 No
37
11 892 RCA; Cx 28/09/09 No
33
12 198 LMS 15/10/09 No
16
13 489 Cx 23/10/09 No
8


Columns A, B and C contain raw data. Column A is a number relating to a
person. Column B is a procedure that has been carried out (note some patients
have more than one procedure seperated by a semicolon e.g. row 2 had RCA and
LAD) and column C is the date of the procedure.

In column D, I need excel 2007 to work out whether the procedure that was
carried out was later repeated (i.e. on a date following the date of the
procedure in this row). I have filled in the answers that should come out in
column D. For example, in row 2 the answer is Yes, as in row 8 the same
person (123) had a repeat "RCA" procedure on a later date in row 8

In column E, I need to calculate the number of days between the dates of
repeated procedures. If there hasn't been a repeated procedure then I want
the number of days between a pre-specified date (in this case 31/10/09) and
the procedure date. Therefore, in row 2 it is the difference in days between
C2 and C8. In row 4 it is difference between 31/10/09 and C4.

If a procedure has been repeated on a person more than twice, I just need
the number of days between the 3rd and 2nd procedure (e.g. person 489 who has
had 3 "Cx" procedures.

Can this be done anyone?

Many, many thanks,