Mere moments ago, quoth I:
If you mean calling .NET methods in a custom assembly (which was not at
all clear), note that you can call directly into a C# assembly if you
like; you don't need to go through an intermediate C++/CLI assembly.
(But you do need to annotate the method in that assembly to make it
callable.)
See
https://jrsoftware.org/ishelp/index.php?topic=scriptdll for more
info, along with the CodeDll and MyDll\C# examples.
In particular, note that you must specify multiple DLLs in the external
if they are dependencies of the entry assembly, and use the
corresponding flag.
Also be careful with strings; the examples show ANSI strings only, which
is probably not what you actually want. Returning strings is also
trickier that it may first appear.
Finally, note that you should verify that the intended minimum version
of .NET is actually installed before trying to call any .NET methods.
While most current versions of Windows do include some version of .NET
by default, it could be an older version than you expect, or it could
have been uninstalled.