Thank you for answering.

Actually - most of tools you named, are so called OBFUSCATORS, which (if I understand them right) just somehow 'scramble' or rename metadata and all names there - so they are harder to disassemble and understand.
They are something like packers or protectors for 'normal' PE files...

What I needed was decompiler for IL, or some tool to 'relate' IL code produced by ILDasm and REAL (I mean executed) code in CLR, because IL is just some kind of p-code....

One decompiler you mentioned is Anakrino, but I couldn't make that one work It just starts ... and ends. No gui, nothing.

But I already solved my problem different way - I learned MSIL and have rewritten needed function in classical C.

Anyway, if somebody knows, how to debug IL, or how to patch it, or use it with non-.NET app, any info is welcome ...

bye