Vista - Template Binding for AccessText.TextAlignment not working

All,

we are generating XAML in a Web Service. This XAML is transported to
the client and displayed there. Now I am generating similar code in
the XAML for any of the Labels:

<Label ... HorizontalContentAlignment="Right">
<Label.Content>
<AccessText TextWrapping="Wrap" Text="Label Text"
TextAlignment="Right"/>
</Label.Content>
</Label>

This seems not right to me. Rather I would like to have XAML like this

<Label ... HorizontalContentAlignment="Right">Label Text"</Label>

and do the rest in a template. So I tried to apply the following style/
data template to Labels:

<Style x:Key="labelStyle" TargetType="{x:Type Label}">
<Setter Property="Label.ContentTemplate">
<Setter.Value>
<DataTemplate x:Uid="labelDataTemplate">
<AccessText TextWrapping="Wrap" Text="{TemplateBinding
Content}"
TextAlignment="{TemplateBinding
Label.HorizontalContentAlignment}"/>
</DataTemplate>
</Setter.Value>
</Setter>
</Style>

Everything works fine with exception of the Template Binding for the
TextAlignment property of AccessText. I assume that this is due to the
fact that Label.HorizontalContentAlignment is of enum
HorizontalAlignment and AccessText.TextAlignment is of enum
TextAlignment, though I did not get any binding errors in VS output
window.

Does anybody know how I could solve this? I think value converters can
not applied here, since they expect objects as input and return
objects.

Thanks,
Michael