Well, in fact there IS a way to copy+paste from Windows to Skyrim, Fallout 4, etc... but a third party software is required. Download AutoHotKey (free open source project) and create a simple script that (only) contains this...:
^b::
SetKeyDelay, 0, 25
Loop, parse, clipboard, `n, `r
{
Send, %A_LoopField%
Send, {Enter}
Sleep 200
}
Return
In the first line you could change the 'b' key for another if you want. Execute the script AS ADMINISTRATOR (it will not work in-game otherwise) and it will keep running in the background waiting for a Control+B press. It's the same as the common Windows Control+V, but in this case it will key in every character in your clipboard. The delay you'll see between keystrokes is necessary for not obtaining garbled text. You could fine tune the SetKeyDelay and Sleep values as you want, according to your system. Those values work for me in my i5-2500K rig. Have fun.