Replacing value in .csv file

[.paul.]

dim lines() as string = io.file.readalllines("csv.txt")
for x as integer = 0 to lines.getupperbound(0)
    if lines(x).contains(".,") then
        lines(x) = lines(x).replace(".", "Value4")
    end if
next
 
io.file.writealllines("csv.txt", lines)