Okay, the idea was to store a 1 or 2-byte number in an AppVar, then compare it to a new 2-byte number and store the biggest number (the idea of a Hi-Score:))
Secondly, I wanted to show that number.
Now, what I'm doing works only "half", in that it does show the correct number, but it's always an increment of 256 off.
This suggests that when using "b_call _DispHL" the "H" is off.
I have no idea why it randomly fills in H (it's not randomly though, but to keep things simple I won't explain/elaborate too much)
Basically, without posting the whole script, this is what I'm doing to show the stored number:
CALL Appvarstartcall ; These 3 lines just set HL to the Hi-Score, so that it's now at the adress of the 2-byte score.
LD B, 23 ; "B" is just how many times I want to inc hl to get to the right adress. For exemple's sake I use 23 here.
CALL lookup ; INC HL a couple of times to get to the right adress...
ld D, (hl) ; Load the most significant bute in D
inc hl ; inc HL to get to the adress of the least significant byte
ld E, (hl) ; And load the least significant byte in E.
ex DE, HL ; Put DE in HL so the next line works :P
b_call _DispHL ; It should show the stored hiscore now, exept that it doesn't. "D" seems to be a bit off.
             .........rest of stuff.......

Appvarstartcall:
ld hl, "NameOfTheAppVar"
rst 20h
bcall(_chkFindSym)
inc de
inc de
ex de, hl
ret
lookup:
inc hl
djnz lookup
ret
The problem is either at how I show the number, or at how I store it.
If I'm not doing horrable things above at displaying the number, it must be the way I store it.
Above is how I display the number, the way I store it is:
Score .equ AppBackUpScreen

CALL Appvarstartcall
LD B, 23
CALL lookup
ld D, (hl)
inc hl
ld E, (hl)
LD HL, (score) ; Score is the current score, to be compared to the previously stored hi-score.
or a
sbc hl, de
add hl, de
CALL p, NewHiScore ; if "Score" > Hiscore, store it.
........rest of script........

NewHiScore: ;  Basically store "Score" at the given adress.
CALL Appvarstartcall
LD B, 23
CALL lookup
LD DE, (score) ; score is the "new" number to store. It can hold any value between 0-9999
LD (HL), D
inc hl
LD (HL), E
ret
So one of the two (or both) is/are wrong.
Either I don't store "Score" correctly, or the way the number gets displayed is wrong.
Anyone that can shine his light and brighten my day here?

Thanks in advance!

I think I've narrowed down the problem...
I feel silly to say, but the problem might not be the way I store/show the number, but the actuall content of (score) itself...
To reset the number, I simply do:
   LD    A, 0
    LD    (score), A
This of course fails as soon as (score) gets bigger than 255...
It also explains why only the most significant byte seems messed up, but isn't random.
I haven't tested it yet (don't have acces to my stuff right now) but that's probably the whole problem... /ashamed  

Hmm, I don't entirely follow your code.
It would be easier to debug if you posted the entire code and a binary.

I just don't want to be that guy that posts infinite strings of code and then states "it doesn't work".
You people got better things to do than debugging over 7000 lines.
But what part you don't understand?
The first part is how to show a number stored in an AppVar at the 24th Byte.
The second part is how to store a number there.
Seems pretty straight forward to me, but if I need to clarify some things, please say so  
If there's indeed no miskate in there, feel free to use these routines.

There's also a "ld (addr),hl"
You should be able to use that to solve your problem
Edit: I might look at the code myself later.

Just one thing: Since the forum activity is very high, if you have an update on your situation (problem fixed, new problem, solution), I suggest that if it has been over 6 hours since your last post, that you bump the topic with a new post, as a simple edit will not bump the topic in the list. It will ensure your update won't get missed. Double-posting is allowed if it has been over 6 hours between consecutive posts by the same person.

Glad to hear it works!

One day I really need to give ASM another try... but so much stuff in my to-do list...