Replacing characters in numeric text strings and SUMming

The dollar and parentheses are part of the text strings in the example,
so from what I can tell they need to be stripped
out and the numbers in parentheses converted to negative before the
formulae above will work!?

Also, as I said above, I need to keep the original cells as they are
with the dollar sign and parentheses.

thanks again.

Ok, I ended up doing this a rather unneat way but it works. I made an
out-of-sight column
corresponding to the original column with this formula:

=IF(ISTEXT(L6),--(IF(LEFT(L6,1)="(",-RIGHT(LEFT(L6,LEN(L6)-1),LEN(LEFT(L6,LEN(L6)-1))-2),RIGHT(L6,LEN(L6)-1))),)

This stripped out the the $,(,) characters and adds a '-' for negative
numbers in parentheses. Then I AutoSum the column and
referenced the result where I needed it.

If anybody knows a neater way I'd be interested to see/hear it.