If those are the only two strings you're dealing with in the block before the string is complete and then used, then you don't need a string builder. StringBuilder starts being more efficient around 6-8 concatenations but before that it's not going to matter much.

Unless you're running this code in a loop - don't bother with a string builder.

+++ Rick ---

>The following code is executed intensively:
>
>

>            ' Check for the last occurence
>            If Mid(lcString, lcString.Length - lcWord.Length) = "." + lcWord Then
>                lcString = Mid(lcString, 1, lcString.Length - lcWord.Length) + "[" + lcWord + "] "
>            End If
>
>            ' Check for the first occurence
>            If Mid(lcString, 1, lcWord.Length + 1) = lcWord + "." Then
>                lcString = "[" + Mid(lcString, 1, lcWord.Length) + "]" + Mid(lcString, lcWord.Length + 1)
>            End If
>

>
>Now, in order to fit some very long string, I have adjusted that method to use a StringBuilder instead.
>
>So, just before that code, instead of lcString, I have a loStringBuilder. This is the last part remaining in the conversion of that method. I am looking for the best way to convert that.