Transforming config files outside solution (MSBuild)

Currently i'm trying to transform config files inside my solution with msbuild. I added transform files in my web projects and added the following arguments in my build definition : /P:CreatePackageOnPublish=true /P:DeployOnBuild=true /P:TransformConfigFiles=true /p:UseWPP_CopyWebApplication=true /p:PipelineDependsOnBuild=false

I'm building on the following configuration : Any CPU|Package

The config files in my web projects are being transformed but the config files outside of my solution (our plugins) aren't. I'm currently building my classes inside my projects into an external map that contains the config files and exe files. My config's are named "CompanyName.Plugin.exe.config".

Is there a way to perform the transform to these files the same way i did with the web.config's inside my solution? (I named them web.Package.config and CompanyName.Plugin.exe.Package.config but that didnt work)

Kind Regards,

Tim