Si ma è una proprietà che viene caricata alla successiva riapertura dell'applicazione... magari però sbaglio.
Prova questo:
Private Sub CambiaIconaApp()
ChangeProperty "AppIcon", dbText, Access.CurrentProject.Path & "\AppIcon.bmp"
Application.RefreshTitleBar
End Sub
Function ChangeProperty(strPropName As String, varPropType As String, varPropValue As Variant) As Integer
Dim dbs As DAO.Database
Dim prp As DAO.Property
Set dbs = CurrentDb
On Error GoTo PROC_ERROR
dbs.Properties(strPropName) = varPropValue
ChangeProperty = True
PROC_EXIT:
On Error Resume Next
Set prp = Nothing
Set dbs = Nothing
Exit Function
PROC_ERROR:
If Err.Number = 3270 Then
Set prp = dbs.CreateProperty(strPropName, varPropType, varPropValue)
dbs.Properties.Append prp
Resume Next
Else
ChangeProperty = False
Resume PROC_EXIT
End If
End Function