I use a split udf to do this. When you use SSRS to pass a multivalue parameter, it'll pass them all in a comma delimited string.

I do the split with the following (which I butchered from somwhere ages ago, apologies, but I haven't got an annotation):

Create FUNCTION [dbo].[Split_udf](@String nvarchar(MAX), @Delimiter char(1))

RETURNS @Results TABLE (Items nvarchar(MAX))

AS

BEGIN

DECLARE @index INT

DECLARE @slice nvarchar(MAX)

--Have to set to 1 to start with

SELECT @index = 1

WHILE @index !=0

BEGIN

--get the index of the first instance of the delimiter

SELECT @index = CHARINDEX(@Delimiter,@String)

--put everything to the left of the delimiter into the slice variable

IF @index !=0

SELECT @slice = LEFT(@String,@INDEX - 1)

ELSE

SELECT @slice = @String

--Put it into the result sel

INSERT INTO @Results(Items) VALUES(@SLICE)

--Cut the string now and put the rest back in

SELECT @String = RIGHT(@String,LEN(@String) - @index)

--If we've run out of characters, we're done!

IF LEN(@String) = 0 BREAK

END

RETURN

END

In your main query you would then need to put the following in the where cause:

fundid in (Select Items from dbo.Split_udf(@fundidlist, ','))

I wouldn't suggest using an "all" option, as SSRS will do this for you.

Hope that helps.