How to make WINE open an exe-file only by the file name omitting the extension EXE?

Do as you say:

1.Deleted prefix `~/.wine and recreated it with
[…]$ WINEPREFIX=~/.wine winecfg

  1. Tried to run without “”

[…]$ wine /home/username/Programs/QucsStudio/bin/qucs.exe
0024:fixme:heap:RtlSetHeapInformation 00000000 1 00000000 0 stub
0024:fixme:win:FlashWindowEx 0021F4D4 - semi-stub
0024:fixme:msvcrt:__clean_type_info_names_internal (657BFC7C) stub
0024:fixme:msvcrt:__clean_type_info_names_internal (6726B1FC) stub
(opened perfectly)

Tried without extension:
[…]$ wine /home/username/Programs/QucsStudio/bin/qucs
wine: failed to open “/home/username/Programs/QucsStudio/bin/qucs”: c0000135

  1. Opening inside the folder

[…]$ cd /home/username/Programs/QucsStudio/bin/
[… bin]$ wine qucs
0104:fixme:heap:RtlSetHeapInformation 00000000 1 00000000 0 stub
0104:fixme:win:FlashWindowEx 0021F4D4 - semi-stub
0104:fixme:msvcrt:__clean_type_info_names_internal (657BFC7C) stub
0104:fixme:msvcrt:__clean_type_info_names_internal (6726B1FC) stub

WOW!!! It opens well without the extension. Why??? What is the problem then?

It seems we are almost there.
Thank you