P.S. the "DIMASO" command "does exist" for draftsight, but it does nothing. Setting it to 1 or 0 does absolutely nothing in any effect to the dimension.
Matthew, typically dimensioning to a center mark and not the center of the circle itself is standard dimensioning practice, while the leaving the extension line solid. I've never heard of extension lines needing to be in a centerline format. You can also use center marks that extend past the edge of the circle and then dimension from that center mark using an extension line (with a continuous line format) if you do not want your extension line to creep into the circle.