Software Deployment

Hi,

I have a question in regards to an Excel add in deployment issue. Basically I've packaged a financial application called Holt Valuesearch. One of the requirements is to load an excel add-in into excel that runs from a network share, the add-in should be loaded after the application has installed. I've created a custom action to load the add-in (I got the code from here!). When I run the MSI in UI mode it works fine, but my problems are encountered when I deploy the MSI as a user based deployment via Active Directory, basically my add-in doesn't load. Below is the custom action and sequence, can anybody shed any light on why it's not working?

Custom Action:

On Error Resume Next
Dim oXL
Dim oAddin
Set oXL = CreateObject("Excel.Application")
oXL.Workbooks.Add
Set oAddin = oXL.AddIns.Add("\\Mandg.co.uk\dfs\APPS_UAT.MG1\Holt Linker\VS7Linker_DM.xla", False)
oAddin.Installed = True
oXL.Quit
Set oAddin = Nothing
Set oXL = Nothing

Return Processing: Synchronous (Check exit code)
In-Script Execution: Immediate Execution
Install Exec Sequence: After InstallFinalize
Install Exec Condition: Not Installed