Dim Packet as string
Dim SentData as string

SentData = this is where you could either say it would come directly from a text box or label or you could have it as a variable for the sub this is in
Packet = "Whateveryourpacketnameshouldbe" & SEP_CHAR & SentData & SEP_CHAR & END_CHAR

SockMain(Index).SendData Packet                    'now im not sure exaclty about the index but i think thats how you do it

Private Sub sockMain_DataArrival(ByVal bytesTotal As Long)
sockMain.GetData strData, vbString
Call HandleData(bytesTotal)
End Sub

Sub HandleData(ByVal Data As String)
Dim Msg As String
Dim Parse() As String

If Parse(0) = "Whateveryourpacketnameshouldbe" Then
    Msg = Parse(1)
    Call DoWhatEverWithMsgData(Msg)
End If
End Sub