MacBook Pro is in suspend, connected to external LCD, mouse. Without opening lid I click mouse button, it wakes up and I can use external LCD. However, now I open lid and it's black. Is there an easy way to bring internal LCD back from this?
As a word of warning - it isn't super great for your MPB hardware to use it with the lid closed.
The laptop was designed to dissipate a significant amount of heat through the inner surface - feel the case near the screen when you are doing heavy work. With the lid closed this isn't possible so the internal temp in the laptop will most likely increase. Have you found that it is warmer or that the fan is running more frequently?
If you really want to use it in the closed shell configuration, and then wake it up smoothly - I think you can wake the screen by connecting it to the external monitor via a KVM switch ( http://www.belkin.com/au/IWCatProductPage.process?Product_Id=172698). By cycling the KVM input (on my KVM it is a simple clicker switch) you may be able to get the laptop to wake up without having top re-sleep it.
You can bring the laptop LCD back into operation by opening system preferences > displays, and clicking on the detect displays button at the bottom. I think if you turn on the menu item, you can do this as well.
Another option that I have not tested would be to press the switch displays button (FN-F7) if i remember on newer macbook pros, and cycle through the options to get to both of them on.