First letter on each sentence UCase

[aaron1259]

hi
i need some help to make text in textbox change to first letter on first word in a sentence UCase.
im a trying to do this: You input Text into a Text Box, you click a radio button, then you click a convert text cmd and it changes the text in the text box to first letter on first word in a sentence UCase.
I have done first letter on each word upper case which was

Option Explicit

Private Sub Command1_Click()
    MsgBox makeFirstUCase("hello i aM aaRon")
End Sub


Private Function makeFirstUCase(myStr As String) As String
    Dim strArr() As String
    Dim i As Integer
    
    strArr = Split(myStr, " ")
    For i = 0 To UBound(strArr)
        If strArr(i) <> vbNullString Then
            strArr(i) = UCase(Left$(strArr(i), 1)) & Right$(strArr(i), Len(strArr(i)) - 1)
        End If
        makeFirstUCase = makeFirstUCase & strArr(i) & " "
    Next
    
    
    
End Function

Please help