A way to set default value of TimeFrame parameter?

Hi everyone:

Is there a way to set a default value for a TimeFrame parameter?

I have the following:

[Parameter("Long TimeFrame")]
public TimeFrame LongTimeFrame { get; set; }

When I view the cBot in cTrader, any TimeFrame parameter always comes up with "H1 (1 hour)" by default, which is not what I want.

When I change the code to be:

[Parameter("Long TimeFrame", DefaultValue = TimeFrame.Hour2)]
public TimeFrame LongTimeFrame { get; set; }

the code won't compile with the following error which I can't seem to find a way around:

An attribute element must be a constant expression, typeof expression or array creation expression of an attribute parameter type

Thank you.