Substituting formula for rolling forecast

Hi All,

I have created below rolling forecast as shown below. In second row period details have been selected from dimension. whereas in first row, year and month captured as per the below formula

[=CONCATENATE(YEAR(TODAY()),".",IF(MONTH(TODAY())=1,"0",IF(MONTH(TODAY())=2,"0",)),MONTH(TODAY()))]

when i am substituting the formula(created in I1) in actual period (I4), giving the name as "#name? in stead of date as 2014.01. i have tried in different ways but no luck

Hence, can you please suggest me the right way to substitute the formula if i am wrong

Regards,

Ravi