How to call a remote powershell script from within a ARS workflow?

Hi all, 

Using ARS 7.4.3. I have a rather long Powershell script which I would like to start from a workflow. Meaning the workflow starts an Active Roles Powershell script which then fires the external script. In a normal powershell command windows, I woud just type:

PS C:\> .\scripts\test.ps1

This would then start the script. If I do the same within Active Roles I get an error saying: 

Execution of workflow instance failed.
Workflow name: *****_Azure - Step2_Migration
Workflow GUID: 3fc267ea-6de9-ea11-a300-00505697358f
Workflow instance GUID: e49ab746-b4d0-4a47-bd67-a426355e60a9
Operation ID: 1-20981
Operation GUID: 4db6e52c-f9b3-4018-8e9d-8534fbf28aeb
Operation: Modify Object
Object name: Test OnlineMigration2
Object parent container: ***********/_Prod/001/Users
Object type: user
Object GUID: e9b54881-fb4b-4357-a32d-9becd1907305
Initiator: *****\A0019000
At line: 37 char:5. The term 'C:\scripts\test.ps1' is not recognized as the name of a cmdlet, function, script file, or operable program. Check the spelling of the name, or if a path was included, verify that the path is correct and try again.


I have also tried Invoke-Expression $MyScript. Same error.

#Execute a script via Invoke-Expression
$MyScript = 'C:\Users\a0019000\Untitled46.ps1'
Invoke-Expression $MyScript

 I have seen multiple question and answers in regards to this in the forum but none of the suggestions seem to work for me.

Any ideas how this should be done??