The information at the support.microsoft.com.... site that I previously mentioned includes an entry that says:
Maximum # of characters per macro subst. line = 8192

Wouldn't that indicate that your method (a good way to build an SQL) is still limited to 8192 characters, or am I misinterpreting the entry (or is it stated incorrectly)? Please confirm that you have built SQL that way to surpass the 8192 limitation. That would be good to know. Thanks.