[StainlessS]

From Wiki:- http://avisynth.nl/index.php/Plugins#LoadPlugin

LoadPlugin

Loads one or more standard (C++) AviSynth plugins.

LoadPlugin(string filename [, string filename...])

string filename =

The path of the .DLL file(s).

No mention at all of return type.

never heard of AvsEdit

Dont bother trying it, its infuriating, written in either Delphi or VB I think [I got the source somewhere, maybe].
EDIT: I use PsPad (mostly for quick hack/init of script, thereafter usually VD2 unless final formatting text, TAB expand to SPACE for D9 or similar).

EDIT: Actually, LoadPlugin (in Avs+ v3.5) returns True, so returning pointer to string or 0 (null pointer) is now moot.

Function LoadPlugReturnValue(string PlugName) { return "'" + string(LoadPlugin(PlugName)) + "'" }

Plug1="C:\Z\Example.dll"          # x64 Example.dll (source returning something like: "'Example' Example filter")
Plug2="C:\Z\TweakColor.dll"       # x64 TweakColor recompile DG (source returning 0)

s1=LoadPlugReturnValue(Plug1)
s2=LoadPlugReturnValue(Plug2)

S="Plug1 '" + Plug1 + " = " + s1 + Chr(10) + \
  "Plug2 '" + Plug2 + " = " + s2
return MessageClip(S)