[Exim] Conatenation of Strings

Hello Everyone;

I was looking at the new wildcard lookup operators in exim 4.3 and was
wondering what the best way to go about concatenating special characters
would be:

data = ${lookup{$header_to:}wildlsearch{/etc/aliases-to}}

In /etc/aliases-to I might have something like this:

someone_here@???: should_go@???

But then sometimes the To: header would have something like this:

"Someone Here <someone_here@???>"

So I thought I could use the wildlsearch to match on the keys in the
aliases-to file with .* on either end; but I'm unsure of how to put that
back in the string expansion for the data: line:

data = ${.*lookup{$header_to:}.*wildlsearch{/etc/aliases-to}}

doesn't work, and I've tried various variations on the same theme.

Thanks for any pointers;

-Craig