problem with dynamic mdx expression

Hi,

i have a calculated member

the function LINREGSLOPE juste calculate the slope ( ie: a) of the equation Y= a*X+b

Gain= LINREGSLOPE([TIME].[Month].&[2006-02-01T00:00:00]:[TIME].[Month].&[2006-06-01T00:00:00],[CHKPT - BATCH IS BOP %],Rank([TIME].[Month], [TIME].[Month].Members))

it's work very well. But my problem is that i want to link the expression of this calculated member with the paramètre in the filter:

So, i want to include the two parametrs in my expression how to extract this information. How can i concat the parametre!month.value with the string ?

http://forums.databasejournal.com/clear.gif

http://forums.databasejournal.com/clear.gif

how can i do this please help

thanks