This code will let you create an attachment on the current test run in ALM. If you want to update things from an external VB script file, then there's a bit more work to it.
If I remember correctly, then you should be able to update the current run status like this...
On Error Resume Next
Set objAttach = QCUtil.CurrentRun.Attachments.AddItem(Null)
objAttach.FileName = strFilePath ' the full path to the file you want to attach
objAttach.Type = 1
numErr = err.Number
On Error Goto 0
blnStatus = numErr = 0
QCUtil.CurrentRun.Status = "Passed"
If you need to use an external VB script to find a particular run, update the status, and upload an attachment, it can be done. I'll try to get some sample code for that if you need it but it will be later.