This would require the scripting language to 1) disallow use of % anywhere in the variable name except at the beginning, and 2) interpret . followed by a % as a combining character in non-space-delimited text that interprets the % following the . as a variable name.
Thanks. As far as the "." followed by "%" as a combining character in global parsing, I don't believe that to necessarily be the case. That would be a sub-branch parsing once you've already identified a variable -- a string leading with "%". For instance, foo.%bar would be a generic string with no special meaning, while %foo%bar and %foo.%bar would both be dynamically named variables. The dot is just for prettiness.
And yes, you would have to take away people's ability to use "%" as a literal character in the middle of variable names. As if a sane person would do this.