if cell includes string, append a character to the value of another cell.

You could just use native fumctions and standard Excel features, they are worth learning!

!/. Add a sheet, I've called it "Before Cleaned"
In A1

=TRIM(SUBSTITUTE(Before!A1,";",","))

Drag Across and Down as required
Copy the result, (not the whole sheet), and Paste Special > Values to
"Report Language" A2

Delete Sheets "Before" & "Before Cleaned"

2/. With "Report Language"
Insert a column between Columns B:C, this will become Column C, the following columns will increment automatically.

In A1 put the language you need to add "Armenian"

In B2 put the text you want to find "April 13", this should be preceded with an apostrophe to avoid Excel forcing a serial date.

In C3

=IF(ISNUMBER(SEARCH($B$1,INDEX($A:$I,ROWS($1:2),MATCH("Reports",$A$2:$I$2,0)))),IF(B3="",$A$1,B3&", "&$A$1),B3)

Drag/Fill Down as required.

You can then use Copy > Paste Special > Values and delete columns as you need.

This takes longer to explain than do!