using tm1 cube attributes in bi

[namomita]

Hi, I am accessing tm1 cube with Cognos 10 Bi. There is a period dimension with elements like YYYY.MM (e.g. 2011.10) for october of 2011. There are consolidations 2011.CY, 2012.CY,2012.01.YTD, 2011.01.YTD  (where cy is calendar year and ytd is year to date). in the bi report when the user selects a period e.g 2012.01 then the report should show revenue information for 2012.01 and 2012.01YTD and 2012.AY. In the period dimension I have attribute fp for each period. 2012.01 has attribute fp of 2012.01.YTD. the problem i am having is how do i display 2012.01.YTD values. ie. when i pass this attribute as parameter, how do i access it in the ytd expression of the report, it says that the value is numeric and it is expecting a mun.
thanks,
namomita