Msbuild with Regex

I am trying to write a target that looks at a svn_tag and sees if that includes the word -dev. I have done like below but I only get the output like this:

Regex:
12:40:44    Input : Build-1.0.0.154 Output :



 <Target Name="Regex">  
  <PropertyGroup>
  <Out>$([System.Text.RegularExpressions.Regex]::Match($(SVN_TAG), `-dev`))</Out>  
  </PropertyGroup>    
  <Message Text="Input : $(SVN_TAG) Output : $(Out)"/>  
 </Target>


How can I do this? Just need true or false answer.