Hi Ray,
i have been playing with Expression this week, and have used it in 3 ways.
1) Saving an Expression website/page inside a nettalk website,
This just works (if you steer away from the expression server dodads) so you can point to them just like any other url.
2) Embed a browse into an Expression Page - you need 3 tags
<!-- NetWebServer --> at the top
<!-- Net:c:Head -->
<!-- Net:YourBrowseProcedure-->
i placed these two together
inside an Expression <!-- #BeginEditable --> tag.
you need nettalk 4.31PR7 as bruce has added some bits to help this along.
Depending on your content you still may need to tweak things - i had to derive my own CreateImage to get the image urls just right.
in this case, an update from the expression looking browse just opens the normal nettalk form.
3) Embed an Update form - which if i understand, is what you want, I was doing the same thing except from a menu, not a browse, but i think the same principle applies, use the same tag strategy, and as you already know, the tag does not tell the form what data to populate, like you i was not sure how to do that, so my solution was to make the updateform smart, dunno if its best but it seems to work:
in my menu or in your browse set a sesssionvalue(s) to use in your updateform (like mike mentioned) before calling the tag endowed expression page.
In the procedure setup right after CODE, for the updateform, i test if the unique key is present/passed, if p_web.Getvalue('Your:keyid') = ''
if not i assume its from an expression tag so, i set the values that the form expects
p_web.setvalue('Your:keyid'', p_web.gsv('usethistargetID'))
p_web.setvalue('Change_btn', 'Change')
i then open the file, read the target record,
do a p_web.filetosessionqueue(targetfile)
close the file
and bob's your uncle.
it works for me, there seems to be room for some gotchas, if the target requires you to login, you might want to do more than just return, In my case i just p_web.sendstring some text back to the expression page."acess denied or some such" i suppose you could go to a loginform...
some housekeeping on the sessionvalues,updating your browse when you return might need to be addressed etc, but maybe it gets you started. and if you look at the values that the browse and the updateform are manipulating you might be able to continue the technique to do something fancier... so you can return to the browse cleanly.
poul