#435 Cannot search for two (or more) look aheads - (?=item 1)(?=item 2)

[Swin]

For example, I am looking though log file where an entire entry in contactonnated onto line, e.g:

2015-11-05T09:08:29.815 user@domain.com ......^M....user@domain.com

etc. I am looking to match a couple of items, say the users email, and perhaps the time stamp , or "stuff"

So, I thought

(?=user@domain.com)(?=stuff)

would do the trick. It doesn't :(. Each on thier one would work,

(?=user@domain.com)
or
(?=stuff)
would both match the line. but when put together they don't.

It maybe that my RegEx is pretty naff (which it is), but an understanding of how to achive this in GrepWin would be great..