Which is best: Formula, Pivots, VBA, or query?

Hi everyone, i'm having difficulty deciding how to approach my problem here. I have two colums of data, the first w/ an id, and the second having a comma-delimited string of other ids (see image w/ five rows of data). What i need to do is get get rid of the csv string, and create the data into two columns, each with no more than 1 id therein, as within the image w/ 16 rows of data.

Basically, i need one record for each Track_id to PSplit_id relationship

I'm getting nowhere w/ functions, as they don't seem to create rows of data, and I'm completely unfamiliar with pivots (someone tome me this could help). I'm starting to think i'll need to import the data into an Access table, and run a query to get the results how i need, then import the query results back into Excel. Is this the best approach, or is it possible without having to resort to Access?

Any advice is appreciate, thanks!
Chris

Pictures of excel sheets aren't much use... non editable. An excel sheet is strongly preferred. But... here's one i made earlier.

In C2, copied down:
=IFERROR(INDEX($A$2:$A$4,MATCH(0,INDEX(--(COUNTIF($C$1:C1,$A$2:$A$4)=LEN(B$2:B$4)-LEN(SUBSTITUTE(B$2:B$4,",",""))+1),0),0)),"")

In D2, copied down:
=IF(C2="","",TRIM(MID(SUBSTITUTE(","&VLOOKUP(C2,A$2:B$4,2,0),",",REPT(" ",99)),COUNTIF(C$2:C2,C2)*99,99)))

You need to adjust the ranges to suit your data!!! I only had 3 rows (A2:A4 and B2:B4). You will have to adjust it to suit you.

HOWEVER... with a lot of rows it will be slow. So. It might make more sense to break it up into several blocks of data that will put your processors under less strain.

Here's your file... in one block. It took about 5 mins to run on my battered old laptop.

Really simple with Power Query (Get & Transform Data).

Format your source data as a table, then use the following query:

let
    Source = Excel.CurrentWorkbook(){[Name="Table1"]}[Content],
    #"Changed Type" = Table.TransformColumnTypes(Source,{{"Psplit_Ids", type text}}),
    #"Split Column by Delimiter" = Table.ExpandListColumn(Table.TransformColumns(#"Changed Type", {{"Psplit_Ids", Splitter.SplitTextByDelimiter(", ", QuoteStyle.None), let itemType = (type nullable text) meta [Serialized.Text = true] in type {itemType}}}), "Psplit_Ids")
in
    #"Split Column by Delimiter"

The last step of the code looks complex, but was easily achieved by simply selecting the Pslit_ids column, and clicking Split Column > By Delimiter, selecting Cutom > ", ", and in Advanced options choose Rows

Edit: attched example file. Never mind 5 minutes to run, this is virtually instant.