>MyTable="c:\temp\temp order by MyKey in 0 shared"
>
>use &mytable && Works
>but
>use(mytable) && Error passed by reference don't work

Yes, because the variable MyTable contains more than just a name.

cMyTable = "c:\temp\temp"
cOrderExpn = " ORDER BY MyKey"

USE (cMyTable) &cOrderExpn in 0 shared

>But:
>used to ..
>MyTable="temp" && Opened with a use already
>used to
>select &MtTable && Old way in macro (still works)
>now..
>select(MyTable) && By Reference (works)
>

Parenthesis here does not indicate a function call but name resolution, and without whitespace, would simply invoke the SELECT() function and return and throw away the work area number without changing CWA. With a space, it would select the work area whose alias was in MyTable and make it the CWA.