When you pass arguments to a macro, the spaces define separate arguments. Thus:
<<someMacro this is a test>>
has 4 arguments, "this", "is", "a", and "test"
However, if you want to treat them all as one big argument, you can re-combine them in the macro itself, like this:
\define someMacro(arg1, arg2, arg3, arg4, arg5, arg6, arg7, arg8, arg9)
<$vars arg={{{ [[$arg1$ $arg2$ $arg3$ $arg4$ $arg5$ $arg6$ $arg7$ $arg8$ $arg9$]trim[]] }}}>
...
\end
The $vars concatenates all the individual args into one long space-separated string and strips off any excess trailing spaces if the number of args passed in was less than 9
-e