Path Utility
Mansanasify
Paste a Windows path and convert the drive prefix to /Volumes/<drive>drive/<drive>data, then rewrite backslashes as forward slashes.
Example: M:\Projects\Shots\scene.mov
Updates as you type
Converted path will appear here.

Drive conversion rule: X:\ becomes /Volumes/xdrive/xdata. Remaining path separators are converted from \ to /.