[Wine] edit in external image editor

[Aerilius]

The 3d modeling program SketchUp allows to edit a texture image with an external editor. The texture is exported into the temp folder and then the image editor is executed with the image path as argument.

I want to edit textures with the native (linux) Gimp. If I add in the preferences of SketchUp "/usr/bin/gimp", it succeeds to start gimp, but the file cannot be opened due to a wrong file path and slashes/backslashes:
/usr/bin/C:\users\aerilius\Temp\texture1.jpg could not be opened.

My idea was to add in SketchUp's preferences the path to a shell script which passes the corrected file path to Gimp:


Code:
 #!/bin/sh
PATHWIN="$*"
PATHUNIX="~/.wine/dosdevices/${PATHWIN//\\//}"
gimp "$PATHUNIX"
exit 0



But SketchUp says "image editor could not be launched". Is there a mistake in the script (my first shell script), or is it not possible that way? Have there already been similar situations with other programs?