After weeks I finally think I have a working SendKeys.
- It does't change NumLock state
- It doesn't interfere with already pressed modifying keys
- Checks not wanted manually pressed modifying keys
- Compatible with build-in SendKeys, but with more features
- Pauses in exact milliseconds, even when going over 23:59:59
- Able to send the characters + ^ % ~
- Also works on Windows 7, Excel 64-bit

Please test and report problems. Thank you.
sendkeys and milliseconds-timer.xlsm