Takes the name of a field in a string, the character after the value, and returns the value in an adjacent column. I used this to parse a few hundred URLs for the value of the username.

FindValue.vb

Sub FindValue()

    Dim ws As Excel.Worksheet
    Set ws = ActiveSheet
    
    Dim i As Integer, lastRow As Integer
    lastRow = 328
    
    Dim fromCol As String, toCol As String, field As String, delim As String
    fromCol = "C"
    toCol = "D"
    field = "username="
    delim = "&"
    
    Dim fieldPos As Integer, delimPos As Integer, startPos As Integer, searchText As String
    
    For i = 2 To lastRow
        searchText = ws.Range(fromCol & i).Value
        
        fieldPos = InStr(1, searchText, field)
        delimPos = InStr(fieldPos, searchText, delim)
        startPos = fieldPos + Len(field)
        
        ws.Range(toCol & i).Value = Mid(searchText, startPos, delimPos - startPos)
    Next

End Sub