You can – at least in 4.3.93 or later - simply go to "Tools > Preferences > Advanced" and Uncheck the "Write LISP Form" check box - or - on any version just use Paste Special and choose Paste Bitmap
I use the Windows Clipboard to carry information between applications. The Window Clipboard is a facility provided by MicroSoft that can store data in an application agnostic way - that means that for example, Excel can put data on the Clipboard (with Copy) and MSWord can read it (with Paste). The data on the clipboard doesn't care whether it came from Excel or Word or visa-versa. You can imagine that the Windows clipboard is like a file. You are putting something into a file that another application can read. But the clip board is unlike a file because it can support multiple data types at the same time. Let me explain: now in release 2.0 and above of the Schematic when you Copy (with Control-C) with the schematic pane having what is called "keyboard focus" - which generally means you last clicked in the schematic window, I put a bitmap onto the clipboard of the current schematic like before (ie like in Release 31.0) but I also now put text onto the clipboard than can be read by LISP to re-create the schematic database. The clipboard is smart enough to hold these two data types (bitmap and text) at the same time. Now, in for example, Paint, when you Paste (with Control-V) Paint asks the clipboard for a bitmap and it gets the picture. So paste puts the picture into Paint. All is what you expect. When however you do Paste in Word, it asks the clipboard for any text it has - and the clipboard sends it the LISP code! This is not what you expect - you expected the picture. In the earlier case after the clipboard said "there is no text" Word would have requested a picture from the clipboard and got the bitmap and so would have pasted the picture. This is what you expected.
Why did I add this LISP form to the clipboard? For two reasons: because the clipboard is visible to all applications you can have two copies of the Schematic running and you can paste a schematic from one to the other. When does this ever happen you say? Well there is one more powerful feature of the clipboard - it is transparent to the network - the clipboard can be moved across the network (you don't have to do anything) so, when I am working at home on my home PC and have Remote Desktop open to work I can cut and paste schematics from one machine to the other.
In version Version 4.3.93 and later you can can simply turn off the LISP to Clipboard options. ("Tools > Preferences > Advanced" and Uncheck the "Write LISP Form")