Edit the External ID

I am syncronizing between ARIS and SAP, but in my case if have countered a problem with External ID (AT_SAP_ID). Is there any way to change this attribut with a script?

I tryed to create a report to do this job, but it didn't work, hear is some of the report:

var new_externalID = "newID";

var ATTR_EXTERNALID = 740;

object.Attribute(ATTR_EXTERNALID, nLocal).setValue(new_externalID );

Any solution to this?

BR