In what context do you use the variable (e.g. in a straight table with dimensions Week and (which?) expressions)?
You could try using a set expression to get the YTD, maybe like
=sum({<Week = {"<=$(=week(today()))"}>} total A*B*C) / 100
To help you more, you probably need to give us some more information, in which context you want to use the YTD value and what your (date) fields are (e.g. in my above sample, if you have also a Date field and you select on it, the above expression will not work without clearing the selection like
=sum({<Week = {"<=$(=week(today()))"}, Date= >} total A*B*C) / 100
Alternatively, you could flag your YTD Dates in the script, maybe using
LOAD
...
-1* InYearToDate (Date, Today(1) ) as IsYTD,
Date,
...
from ...;
Then use
=sum( total A*B*C*IsYTD) / 100
as YTD expression.
Hope this helps,
Stefan
