I used the sample code for IEdmBatchUpdate found in the API documentation and I have been able to update variable on a batch of files as desired except that it does not work for DWG files. Every other type of files I have applied this process to had no problems whatsoever. Why is this? In the mean time I have tried to sucessfully set variables on DWG files using another strategy. I succeeded using the sample code of IEdmEnumeratorVariable8 but there is no search feature and it takes about 100 times more time.
I have attached a fie containing the 2 code samples but you can find them in the API document in the sections IEdmBatchUpdate and IEdmEnumeratorVariable8