>For setting there is no problem, my problem was with retrieving back.
You can pass the 255 limit as long as you do it in code. It's only PEM sheet that doesn't accept over 255.

I tried this as a test form (added grid with 3 columns) and set your property value as you have. Looking "under-the-hood" at the SCX as a table, the Property field does not allow the longer property value (it cuts the string at 256). Unlike the _memberdata value, it seems that other properties are not using the longer format of the 8192 char length.

If you hacked the scx and forced the property to the same format requirements of the _memberdata, it might work.