Not sure what TwxIEWebService is but this will fetch your your affected objects in a JSON format given a CR
https://{HOST}/Windchill/servlet/odata/v3/ChangeMgmt/ChangeRequests('OR:wt.change2.WTChangeRequest2:{YOUROBID}')?$expand=AffectedObjects
It returns something like below
...
"AffectedObjects": [
{
"ChangeStatus": {
"Path": "https://{HOST}/Windchill/netmarkets/images/chg_pending9x9.gif",
"Tooltip": "Pending change exists"
},
"CreatedBy": "Some Name",
"CreatedOn": "2019-05-02T00:55:00Z",
"HasHangingChange": false,
"HasPendingChange": true,
"HasResultingChange": false,
"HasVariance": false,
"ID": "OR:wt.doc.WTDocument:54630",
"Identity": "Document name, 5.G",
"LastModified": "2019-05-08T23:27:11Z",
"Latest": true,
"LifeCycleTemplateName": "Lifecycle Name",
"Location": "/folder/location",
"ModifiedBy": "Some Name",
"Name": "Document name",
"Number": "1111111",
"ObjectType": "Subtype name",
"Revision": "5",
"State": {
"Value": "RELEASED",
"Display": "Released"
},
"TypeIcon": {
"Path": "https://{HOST}/Windchill/wt/clients/images/generic.gif",
"Tooltip": "Subtype"
},
"Version": "5.G",
"VersionID": "VR:wt.doc.WTDocument:38438"
},
...