> Below is a piece of a ZTM file.
>
> 1.
> \,C,:\users\airch\desktop\,RET,ALT_L,U,ALT_M,F8,F,:\desktop\,RET,R,RET,Y,
>
> How do I execute @fill_laptop_desktop.ztm next ?
>

Type it into the F12 macro prompt, i.e.

F12
@fill_laptop_desktop.ztm
RET



Why not use the Treespec "F6 Windows folders" to get to the desktop, instead of hard coding?
Why are you using a "," before ":"?

This should work
\,F6,d,RET,ALT_L,u,ALT_M,F8,F:\desktop,RET,r,RET,y,


But why not use this commandline?
robocopy "%userprofile%\Desktop" "F:\desktop" /mir



> 2. Also, why are there extra commas thrown in some of the texts
> sometimes?
>
> For example, the word "f,or", "l,aptop" and "d,esktop" below
>
> \,BKSP,BKSP,BKSP,BKSP,BKSP,BKSP,BKSP,BKSP,f,or,SPACE,l,aptop,SPACE,d,esktop\,RET,RET,f,*.lnk,COMMA,*,.url,RET,CTRL_T,CTRL_D,N,f,RET,

I presume you recorded the macro, which would explain the "," before ":" point, I suspect that ZTree knows that the first characters are menu command letters, and inserts the comer, just in case one of the menu commands is meant.

Are those BKSP's to get to the parent of Desktop? If so why not do one of these
\,F6,u,RET
\,F6,d,RET,LEFT

You could also create a Ctrl-Letter marked Treespec history item to "for laptop desktop", then go to it using assuming you marked with "A", by doing this
\,ALT_A

With Treespec F5 Edit, you can make a history item, that uses an environment variable, like this
%userprofile%\for laptop desktop


Ben