Using streamreader to read line by line of a text file. When I get to a certain line (i.e., 123|abc|99999||ded||789), I want to replace ONLY the first empty area with text.

So far, I've been toying with

```
If sLine.Split("|")(3) = "" Then
    'This is where I'm stuck, I want to replace that index with mmm
End If

```

I want the output to look like this: 123|abc|99999|mmm|ded||789