Hi there Bellaksl,
You should be able to achieve this relatively easily with a code stage.
Incorporate something similar to the below, using an incoming DataTable (your collection) and outgoing String (your comma separated text value):
[Outgoing Comma Separated String] = String.Empty
Dim intCounter As Int32 = 0
While intCounter < [Incoming DataTable].Rows.Count
If intCounter > 0 Then
[Outgoing Comma Separated String] += "", ""
End If
[Outgoing Comma Separated String] += String.Join("", "", [Incoming DataTable].Rows(intCounter).ItemArray)
intCounter += 1
End While
The above will:
Set our outgoing String to nothing
Initialise our counter to 0
Iterate through each row in our incoming DataTable
If we are not on the first row, add a comma, otherwise continue
Add each DataRow value to our outgoing String with a comma separating
Increment our counter
End iteration
You can see it running via this link.
Keep in mind the majority of this is constructing a DataTable, which you will not require!
ALSO, there is no validation or handling included - most likely, you will want to validate the incoming DataTable is initialised and populated accordingly.
Thanks in advance and good luck,
Josh