CommonTasks.csproj

<?xml version="1.0" encoding="utf-8"?>
<Project xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
    <UsingTask TaskName="ReplaceFileText" TaskFactory="RoslynCodeTaskFactory" AssemblyFile="$(MSBuildToolsPath)\Microsoft.Build.Tasks.Core.dll">
      <ParameterGroup>
        <InputFilename ParameterType="System.String" Required="true" />
        <OutputFilename ParameterType="System.String" Required="true" />
        <MatchExpression ParameterType="System.String" Required="true" />
        <ReplacementText ParameterType="System.String" Required="true" />
      </ParameterGroup>
      <Task>
        <Using Namespace="System" />
        <Using Namespace="System.IO" />
        <Using Namespace="System.Text.RegularExpressions" />
        <Code Type="Fragment" Language="cs">
          <![CDATA[
                File.WriteAllText(
                    OutputFilename,
                    Regex.Replace(File.ReadAllText(InputFilename), MatchExpression, ReplacementText)
                    );
              ]]>
        </Code>
      </Task>
    </UsingTask>
</Project>