BW-IP:free text can enter by Analyzer but can't do it in Analysis Office

Hi Experts

I created a characteristic without master data and text. Which is used for record comments during planning. I can write free text into this characteristic by BEx Analyzer. But I can't do this in AO. AO not allowed input a record which not exist in master data into characteristic.

I did searched a lot on SCN for work around this issue. Set Characteristic as Key Figure might solve my problem but I am using BW7.0. Which still not support this feature. Does anyone has any other solution on this?

Thanks