C# send request from Burp, Fiddler, other proxy or Chrome Network tab etc without having to create it programatically -

what simplest way send complete http request saved text in c#? need build programatically using httpwebrequest, webclient, httpclient or can sent is?

an example 1 website, note empty filename attachment2. throw error multipartformdatacontent though request requires it.

ps: example won't used spamming. it's fact government agencies in sweden have not yet adopted api:s , rely on contact forms reach them matters. speed work on end.

post /test/contactus.html? http/1.1 host: www.example.se user-agent: mozilla/5.0 (windows nt 10.0; wow64; rv:52.0) gecko/20100101 firefox/52.0 accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8 accept-language: sv-se,sv;q=0.8,en-us;q=0.5,en;q=0.3 referer: https://www.example.se/test/contactus.html? cookie: jsessionid=8442f618956386f38637ccf89ca3aaed; sv-uts="ymfzzty0c3ryaw5n=="; inesssl=8695386816.20480.0000; _ceg.s=oo15k9; _ceg.u=oo15k9; _ga=ga1.2.548187400.1491551447 content-type: multipart/form-data; boundary=---------------------------187541726320139 content-length: 1175  -----------------------------187541726320139 content-disposition: form-data; name="action"  send -----------------------------187541726320139 content-disposition: form-data; name="email_12.4c5def2714bbf25766d2525"   -----------------------------187541726320139 content-disposition: form-data; name="message"  testing -----------------------------187541726320139 content-disposition: form-data; name="attachment0"; filename="test1.txt" content-type: text/plain  test1 text -----------------------------187541726320139 content-disposition: form-data; name="attachment1"; filename="test 2.txt" content-type: text/plain  test2 text -----------------------------187541726320139 content-disposition: form-data; name="attachment2"; filename="" content-type: application/octet-stream   -----------------------------187541726320139 content-disposition: form-data; name="attachment"  attachment0 -----------------------------187541726320139 content-disposition: form-data; name="attachment"  attachment1 -----------------------------187541726320139 content-disposition: form-data; name="type"  type1 -----------------------------187541726320139--