How to replace empty rows until next entry (and continue)?

[#1]

Dear JMP community,

(W10, 64-bit, JMP 15.0 Pro)

  I have a large data table that is imported from an excel file and I need to have empty rows of a column filled with the entries of the previous list. I am trying to write JSL to go from a column as on the left to the one on the right, as shown below:

  I'm thinking it should be pretty easy to code, but the issue I'm having is correctly stopping at the end of the previous product and starting with the new product. I must not be looping through correctly.

  Any suggestions/help is welcome.

Thanks!,

DS

[#2]

A couple of the JMP systems engineers were going round and round on this problem and this was the best solution. This final version by @Brady Brady is heads a tails faster and more robust than the simple formula we started with. I've been using it for years and found it to work well in a number of situations.  Glad it worked for you!