The following should select the word the cursor is in, plus any following punctuation and sets the next character as upper case. You can add to the punctuation as required.
Code:
Sub Macro1()
Const sList As String = " ,.!?"
Dim oWord As Range
Set oWord = Selection.Words(1)
With oWord
.MoveEndWhile sList
.Text = ""
.End = .End + 1
.Case = wdUpperCase
End With
Set oWord = Nothing
End Sub