The VBA COM line
Set Vissim = CreateObject('Vissim.Vissim.1000')
results in the following error message:
'ActiveX component can't create object'.

1) Register PTV Vissim as COM server (try with administrator credentials):
Help > Register COM Server
2) Check the used class ID to meet the correct release and architecture:
c:\Users\Public\Documents\PTV Vision\PTV Vissim 10\Examples Training\COM\Basic Commands\COM Basic Commands.bas
3) Install the current service pack.
4) Use instead of late binding ('CreateObject') early binding ('Dim Vissim As New VISSIMLIB.Vissim') with a set reference to the VissimXXX.exe (Excel VBA editor: Extras > References)
Example test scripts: