Simple grid from SSAS cube using MDX command - ssas

Question

is there a better way to display simple grid (looking basically like SQL select statement) from SSAS cube using MDX command instead of using this Drillhrough workaround?
Here is what I've been using so far:
DRILLTHROUGH
Select
([Measures].[Some Measure]) on columns
From (
Select
{
[PeriodSpan].&[201301] : [PeriodSpan].&[201304]
}
on columns
From [CubeName]
)
RETURN
[$Dimension1].[Attribute1],[$Dimension1].[Attribute2],[$Dimension1].[Attribute3],[$Dimension1].[Attribute4],[$Dimension1].[Attribute5],
[$Dimension2].[Attribute1],[$Dimension2].[Attribute2],[$Dimension2].[Attribute3],
[$Dimension3].[Attribute1],[$Dimension3].[Attribute2],[$Dimension3].[Attribute3],[$Dimension3].[Attribute4],
IIF([Dimension4].[Attribute1]=[Dimension4].[Attribute1].&[False],[Dimension4].[Attribute2],[Dimension4].[Attribute3])
Problem is that now I can't figure out how to get IFF condition to work. When I try to run the command error message appears saying "Too many arguments were passed to the IIF MDX function. No more than 1 arguments are allowed." I also tried to create new member on cube level by calculation script:
SCOPE (some hierarchy here which I'm still not clear on how to use);
IF [$Dimension4].[Attribute1] IS [$Dimension4].[Attribute1].&[False] THEN this = [Dimension4].[Attribute2] END IF;
IF [$Dimension4].[Attribute1] IS [$Dimension4].[Attribute1].&[True] THEN this = [Dimension4].[Attribute3] END IF;
END SCOPE
I also tried calculated member and named set but with no results.
I'm fairly new to SSAS and MDX but I hope you see what I'm trying to accomplish. Thanks in advance. Any help would be much appreciated.