[Evolution] Searching using Expressions...or using and / or.....

[Steve T <stevetucknott yahoo co uk>]

Evolution 3.2.3, Gnome 3

I want to be able to set up searches that use a mixture of ands and ors - ie typically say I wanted to create a search for this 'group', and then only select messages sent by me or one other person. In pseudo code:

WHERE subject matches '[Evolution]*'
AND    (sender matches 'stevetucknott*' OR sender matches 'joebloggs*')

What is the easiest way of going about this? I looked at 'Expressions' but can't then find the documentation to show what I can do with them.
Should I be using 'regex' rather than an _expression_ - and is there anywhere that tells me what fields are available to be matched/compared?