How to enable calculated dimension of SAC model

[hymo0402]

I have a difficulty on additional data import from file to existing model

1) Create new model from file

2) define calculated dimension

3) import additional data from new-file

When I execute step 3 (above) , I encounter following cases.

Case a) The file doesn't include calculated dimension column

--> SAC request to assign calculated dimension

If I define default value, the value is set. But no calculation is executed.

Case b) The file include calculated dimension column

--> no calculation is executed, value is based on the file

How to solve these problems.

Model image (Calculated dimension is calculated from Dimension 1)

Dimension 1 Dimension 2 ... Calculated Dimension(the value is sub string (Dimension 1,2,3))

1ABC-def A100 ABC

2ABC-def A200 ABC

2BCD-efg A200 BCD

1BCD-fgh A100 BCD

3ABC-def A300 ABC

-----

New file

Dimension 1 Dimension 2 ... Calculated Dimension

1DEF-def A100 DEF

2EFG-def A200 EFG