To get the number 1792, you need to use $gettok()
$gettok(0 +fs 0 0 0 C:\WINNT\explorer.exe +fs 0 0 0 1792 +fs 0 0 0 0.23MB,11,32)
If you've not used $gettok() before, its simple.
Tokens are simply characters (either numbers/letters/special characters, etc), in a string, that are seperated by the use of a special character (such as a comma, space, or pretty much any other character).
For instance, there are 32 "tokens" within the above sentance (when using the space as a seperator).
You'll see mIRC use $1, $2, ... $n to obtain tokens in some cases. $1 is the first token (for the above sentance, it would be "Tokens").
The first part of $gettok() is the text you want to get the token from, the second part is the particular token you want (ie, the tenth token), the last number is the seperator (in this case, a space)
mIRC - fun for all the family (except grandma and grandpa)