How can we set second picklist value dynamically with string value is know in CRM Dynamics 4.0 - workflow

Question

I have two pick-list in Car details entity. I'm setting the Model (cir_model) Picklist value with from the input parameter (that is CrmNumber) of Custom Workflow activity and it's working as expected, and the second pick-list Marque (cir_marque) will be set logically using the Model pick-list.
Logic should be if Model is set to 'Ac Ace' then Marque should be set to 'Ac'. Take value 'Ac' using Split() from the string 'Ac Ace'.
Normally in C# this can be done easily but in CRM 4.0 how this can be achieve (How I'll set 'Ac' to Marque)
public static DependencyProperty modelProperty = DependencyProperty.Register("model",
typeof(int), typeof(CreateCardetails));
[CrmInput("Model")]
public int model
{
get
{
return (int)base.GetValue(modelProperty);
}
set
{
base.SetValue(modelProperty, value);
}
}
public static DependencyProperty ContactProperty =
DependencyProperty.Register("Contact", typeof(Lookup), typeof(CreateCardetails));
[CrmInput("Contact ID")]
[CrmReferenceTarget("contact")]
public Lookup Contact
{
get
{
return (Lookup)base.GetValue(ContactProperty);
}
set
{
base.SetValue(ContactProperty, value);
}
}
protected override ActivityExecutionStatus Execute(ActivityExecutionContext
executionContext)
{
//Create an car details record which will be linked to the contact record
DynamicEntity cardetails = new DynamicEntity("cir_cardetails");
cardetails["cir_carsdetailsid"] = Contact;
//Setting the picklist value of Model
Picklist modelPickList = new Picklist();
modelPickList.Value = model.Value;
cardetails.Properties.Add(new PicklistProperty("cir_model",modelPickList));
/*
Here the logic should be done for setting Marque (cir_model) value
Picklist marquePickList = new Picklist();
marquePickList.Value = ???
cardetails.Properties.Add(new PicklistProperty("cir_marque",marquePickList));
*/
//Creating the car details record
Guid carkey = crmService.Create(cardetails);
}
How we can set the Marque value logically, I have left the code blank for this like below
/*
Here the logic should be done for setting Marque (cir_marque) value
Picklist marquePickList = new Picklist();
marquePickList.Value = ???
cardetails.Properties.Add(new PicklistProperty("cir_marque",marquePickList));
*/
Please arrange to help me out on this, all suggestions are welcome.

Answer 1

There is no language CRM 4.0, in CRM 4.0 you code in c#. The only thing that change is the way you work with new types.
In Workflow you don't work with controls, you work with entities and the related attributes. So you "just" need to get the attribute cir_model, do a subtring and find the available options in Marque and set the corrected value. Check this sample from SDK.

Answer 2

You can use JavaScript or C# (Plug-In, Workflow) to accomplish this. There are some considerations to think of when choosing which approach to use.
If you want the user to be able to see the result in real time (when they select) then you can use JavaScript.
If you don't care for the user to see the result, or there is data coming in from an outside source (not the user form), then think about using a plugin.
I don't think you should have to use a WF to do this, plugins are just as easy to write and will happen instantaneously instead of waiting for the async process to complete.