Hi Rick, how is it going?

I have tried to develop something through SAS PROC IML in order to calculate a Credit Rating Transition Matrix for a specific sample, considering the cohort and hazard rate approaches, and also some confidence levels using bootstrap. This website (https://analyticsrusers.blog/2017/08/15/use-r-to-easily-estimate-migration-matrices-with-rtransprob-part-1/) provides some specific examples regarding the "RTransprob" package which contains a set of functions used to automate commonly used methods to estimate migration matrices used in credit risk analysis. I'd like to do the same, however, through SAS instead of R. I have a SAS dataset containing the following attributes:
CustomerId,Date,Rating,RatingNum
1,30-05-2000,CCC+,7
1,31-12-2000,B+,6
2,21-05-2003,B+,6
3,30-12-1999,BB+,5
3,30-10-2000,B+,6
3,30-12-2001,BB+,5
4,30-12-2001,BB+,5
4,30-05-2002,B+,6
5,24-05-2000,AA+,2
5,30-05-2001,A+,3
5,30-10-2001,AA+,2
6,30-12-1999,BBB+,4
6,30-12-2001,BBB+,4
7,30-12-2002,BBB+,4
7,23-06-2003,BB+,5

I would be so grateful if you are able to send me a code developed in SAS in order to achieve the same results.
Thanks in advance.
Rgs,
Raphael