I havent tested this but its the jist of what you need to do: load the file, find what you need to change, change it, and save the file.
[VB]
Dim lines As String() = System.IO.File.ReadAllLines(filename)
Loop through lines
For I As Integer = 0 To Lines.Length - 1
Dim line As String = lines(i)
Sparate command and value
Dim parts As String() = line.Trim().Split(new Char() {" "c}, StringSplitOptions.RemoveEmptyEntries)
Somewhat validate data
If parts.Length = 2 Then
Check if its what were looking for
If parts(0) = nameImLookingfor Then
Update value
lines(i) = nameImLookingFor & " " & newValue.ToString()
Return Stop looking
End If
End If
Next I
When done, use File.WriteAllLines to update file.
[/VB]