Thank you for clarifying. One thing I learned from this is that the use of the backslash and a number in the replacement field refers only to a terms defined by being enclosed in parentheses, which is why \1 in this expression ignores anything before the open paren.

I am still not entirely clear, however, about the use of spaces, which I didn't state clearly enough. Your expression has a space between the period and the close bracket, and one between the @ and kg. A special wildcard lookup table I have suggests that these may be necessary to separate items in an expression, but that if a space needed to be indicated, ^w would have to be used. Is this correct?

Thank you, sir.