Hi David, cmd.exe's SET command seems to be lacking compared to sh and export. Good news is that using this (all one line),
DOOBLE_GOOGLE_TRANSLATE_URL=https://%1.translate.goog/%2?_x_tr_sl=auto&_x_tr_tl=%3&_x_tr_hl=%3&_x_tr_pto=wapp
in the environment tab of Dooble's program object does work.
Wonder how that can be automated? Or pass the URL in a set statement?
As for os2.org, which was my test URL, it does work, load os2.org, click Tools-->Translate, then in the new translated tab, click the topic works here. Not as nice as SeaMonkey.