You can try the below generic VB .NET methods for getting text and a particular word in file text with seek operation.
Imports System.IO
Imports System.Text.RegularExpressions
Public Class FileReader
Public Function GetText(ByVal PathToFile as String)
Dim fs as New FileStream(PathToFile, FileMode.Open)
Dim sr as New StreamReader(fs)
Dim FileText as string
FileText = sr.ReadToEnd
Return FileText
End Function
Public Function FindWordPosition(ByVal FileText as String, ByVal Pattern As String)
Dim match as Match
Dim myRegex as New Regex(Pattern)
match = myRegex.Match(FileText)
Return match.Index
End Function
End Class