OBBH Subsitution available for table MARA, MSEG?

HI,

The substitution function seem like can be used to substitute a value for table BSEG or header table BKPF only. Am I correct?

I need to write a substitution with check table for MARA and MSEG. How am I archeive this?

I write:-

Prerequisite:

MARA-MATKL = 'RAW005' AND MSEG-BWART = '201'

Subsitution:

G/L: Constant value 5200001

System does not allow to save, because of this:-

Formula cannot be saved because it is incomplete

Message no. SFB503

Diagnosis

You have attempted, either through explicit save or by exiting the Formula Builder, to save a formula that is not complete and not without syntax errors.

Procedure

Correct the formula so that the status light is "Green" and save the formula once again. Or exit the Formula Builder using the function "Cancel", without saving the changes.

Thanks