First, I dont know a utility to automate this process.
Likewise your own answer you only have to create links in one special directory and include this to the PATH
. But to really get it working in commandline, run-dialog and with doubleclicking you need to use Batch-Scripts:
To start file D:\Inkscape\inkscape.exe
@"D:\Inkscape\inkscape.exe" %*
Save that in a file named inkscape.cmd
in this special directory. Then inkscpae is accessable from within the commandline or the run-dialog. All arguments ar piped to the original file.
This works best for CLI programms (yes, inkscape has an CLI) because a cmd.exe process starts to start the wantet programm and doesnt exit until the termination of the started program. For GUI programms it is better to use:
@START "D:\Inkscape\inkscape.exe" %*
Then the cmd.exe process exits after starting the program. All arguments are piped, too.
I use this for an flashdrive installation of LaTeX and for some simple unix-commands in windows (7/64; xp/32). And it works well.