An alternative would be a preprocessor, such as C uses to handle the
#define and #include statements. It could parse the source in the
"Every &count times" format and convert it to "Every #{count} times"
which Ruby would have no difficulty with. But parsing the source just
to do variable substitution must be the hight of Yak shaving given
that Ruby provides a variable substitution mechanism.

Or you could hack the source for Ruby itself and insert this as an
alternative syntax. I don't hack the source myself so I have no idea
of how hard this is or how portable it will be with regards to updates
but given the difficulty you seem to be having with the existing
system you might just consider it worth while.