expand cvs cell

After 12 hours, I will offer this -- Are you really using Excel 2003? That what is in your profile. It might be important, as newer versions of Excel have tools that may make this easier, but are not available to the older versions of Excel.

If you are using a newer version of Excel (or can borrow a computer with a newer version), this looks like the kind of thing that Power Pivot (2013 and earlier)/Get and Transform (2016) can readily do. I have no experience with these tools, so I cannot explain the specifics of how to do it, but that seems like the easiest way. As a guess, it looks like a "Text to columns" step followed by an "Unpivot" step, but that's as good a guess as I can offer.

If nothing else, that should bump your thread back to the top where others can see it. I recommend verifying/correcting your Excel version, as that may be important to coming up with a final solution.

Why do you think that unpivot won't help? As I indicated, I don't use these tools, but your example looks very much like the other unpivot examples I've seen here and around the internet:
One from this forum earlier today: https://www.excelforum.com/excel-gen...ivottable.html
In this link from the other thread: https://www.excelcampus.com/tables/unpivot-power-query/ your example should look an awful lot like the example just before the "Additional Resources" section after a Text to columns.
I don't know if Get and Transform can combine the Text to columns and the unpivot steps into one command. Even if you have to do it in two separate steps, it seems like the easiest way to do it -- unless someone more familiar with Get and Transform can suggest a single step command. I would recommend that, rather than dismissing this too quickly, that you look at it further before explore what I expect are more difficult ways to do this.

Please update your profile to indicate the Excel version you are actually using (I presume you mean 2016...)

Power Query (Get & Transform) is perfect for this: Format your source data as a table, then use the following query:

let
    Source = Excel.CurrentWorkbook(){[Name="Table1"]}[Content],
    #"Replaced Value" = Table.ReplaceValue(Source,", ",",",Replacer.ReplaceText,{"Column2"}),
    #"Split Column by Delimiter" = Table.ExpandListColumn(Table.TransformColumns(#"Replaced Value", {{"Column2", Splitter.SplitTextByDelimiter(",", QuoteStyle.None), let itemType = (type nullable text) meta [Serialized.Text = true] in type {itemType}}}), "Column2")
in
    #"Split Column by Delimiter"

That looks more complex than it is, to write - that was generated by following toolbar steps only.

See attachment for worked example.