KeyRemap4MacBook - MyType Left Shift + Left Alt/Option to Function Keys

gistfile1.txt

<?xml version="1.0"?>
<root>
    <item>
      <name>Holding LShift_LCommand+1,2,3,4,... to F1,F2,F3,...,F12</name>
      <appendix>Holding LShift+LOption+1 to F1</appendix>
      <appendix>Holding LShift+LOption+2 to F2</appendix>
      <appendix>Holding LShift+LOption+3 to F3</appendix>
      <appendix>Holding LShift+LOption+4 to F4</appendix>
      <appendix>Holding LShift+LOption+5 to F5</appendix>
      <appendix>Holding LShift+LOption+6 to F6</appendix>
      <appendix>Holding LShift+LOption+7 to F7</appendix>
      <appendix>Holding LShift+LOption+8 to F8</appendix>
      <appendix>Holding LShift+LOption+9 to F9</appendix>
      <appendix>Holding LShift+LOption+10 to F10</appendix>
      <appendix>Holding LShift+LOption+- to F11</appendix>
      <appendix>Holding LShift+LOption+= to F12</appendix>
      <identifier>private.shift_option_to_functions</identifier>
      <autogen>__KeyToKey__ KeyCode::KEY_1, ModifierFlag::SHIFT_L | ModifierFlag::OPTION_L, KeyCode::F1</autogen>
      <autogen>__KeyToKey__ KeyCode::KEY_2, ModifierFlag::SHIFT_L | ModifierFlag::OPTION_L, KeyCode::F2</autogen>
      <autogen>__KeyToKey__ KeyCode::KEY_3, ModifierFlag::SHIFT_L | ModifierFlag::OPTION_L, KeyCode::F3</autogen>
      <autogen>__KeyToKey__ KeyCode::KEY_4, ModifierFlag::SHIFT_L | ModifierFlag::OPTION_L, KeyCode::F4</autogen>
      <autogen>__KeyToKey__ KeyCode::KEY_5, ModifierFlag::SHIFT_L | ModifierFlag::OPTION_L, KeyCode::F5</autogen>
      <autogen>__KeyToKey__ KeyCode::KEY_6, ModifierFlag::SHIFT_L | ModifierFlag::OPTION_L, KeyCode::F6</autogen>
      <autogen>__KeyToKey__ KeyCode::KEY_7, ModifierFlag::SHIFT_L | ModifierFlag::OPTION_L, KeyCode::F7</autogen>
      <autogen>__KeyToKey__ KeyCode::KEY_8, ModifierFlag::SHIFT_L | ModifierFlag::OPTION_L, KeyCode::F8</autogen>
      <autogen>__KeyToKey__ KeyCode::KEY_9, ModifierFlag::SHIFT_L | ModifierFlag::OPTION_L, KeyCode::F9</autogen>
      <autogen>__KeyToKey__ KeyCode::KEY_0, ModifierFlag::SHIFT_L | ModifierFlag::OPTION_L, KeyCode::F10</autogen>
      <autogen>__KeyToKey__ KeyCode::MINUS, ModifierFlag::SHIFT_L | ModifierFlag::OPTION_L, KeyCode::F11</autogen>
      <autogen>__KeyToKey__ KeyCode::EQUAL, ModifierFlag::SHIFT_L | ModifierFlag::OPTION_L, KeyCode::F12</autogen>
    </item>
</root>

It's probably best to check "General » Don't remap internal keyboards" to keep your macbook keyboard normal, too.