Secondary click and primary click at the same time? Is it possible to do this without owning an external mouse or having the latest multi-touch trackpads?

I need to do this for games originally made for windows, but either run through wine or ported to mac. For the most they doesn't just require this, but also to hold both down for a specific time.

I'm using a MacBook Core 2 Duo, which doesn't have a highly customisable trackpad settings.
No you can't. The trackpad only has one physical button, so it cannot detect a primary and secondary click at the same time, neither can any Apple mouse for that matter.

But, two-button mice come cheap...

Alternatively, perhaps the game allows custom keybindings, or has alternate keyboard shortcuts available.