To copy&paste text snippets to and from different virtual slots is no effort to put into practice with AHK. AHK means “AutoHotkey” and is a scripting language, which basically runs in the background of Windows. You write a custom script, and then let it load automatically when Windows boots. I'm no fan of background processes, since they eat up RAM and system performance, but AHK is really lean, about 1-2 MB in size only and you can do almost everything (almost) with it.
I write an example script. Left Alt in combination with the keys “1” or “2” or “3” copies currently selected text to slot1, slot2 or slot3. Shift + Left Alt + “1” or “2” or “3” pastes snippets from slot1, slot2 or slot3. This script probably can be written much more efficiently and elegantly. However it works and serves as example.
global slot1
global slot2
global slot3
!SC002:: ; left Alt pressed together with the “1” key
bak := Clipboard ; backups current clipboard content
Clipboard := "" ; clears the clipboard
Send, ^c ; copies currently selected text to clipboard
ClipWait, 0.1 ; waits 0.1 seconds for any data to appear to the clipboard, else return an error …
slot1 := Clipboard ; copies currently selected text snippet to a variable called “slot1”
Clipboard := bak ; restores original clipboard content
Return
!SC003::
bak := Clipboard
Clipboard := ""
Send, ^c
ClipWait, 0.1
slot2 := Clipboard
Clipboard := bak
Return
!SC004::
bak := Clipboard
Clipboard := ""
Send, ^c
ClipWait, 0.1
slot3 := Clipboard
Clipboard := bak
Return
+!SC002:: Send, %slot1%
+!SC003:: Send, %slot2%
+!SC004:: Send, %slot3%