Is there a way to send an Http Post with an atachment to a restful web service?.

In my case I am making a Web Service call using the plug-in therefore I'm passing a string which contains the SOAP envelope and one of the fields (Stream) in the envelope is the content of the file. That said, since I'm sending a SOAP envelope my headers are:

="Content-Type"
="application/soap+xml; charset=utf-8"

and my SOAP envelope looks like this

<soap:Envelope xmlns:soap='www.w3.org/.../soap-envelope' xmlns:soap1='schemas.microsoft.com/.../'>
<soap:Header/>
<soap:Body>
<soap1:CopyIntoItems>
<soap1:SourceUrl>Default</soap1:SourceUrl>
<soap1:DestinationUrls>
<soap1:string>xxxx.xxxxx.net/.../soap1:string>
</soap1:DestinationUrls>
<soap1:Fields>
<soap1:FieldInformation Type='Text' DisplayName='xxxxxx' InternalName='xxxxx' Id='22222222-2222-2222-2222-222222222222' Value='xxxxx'/>
</soap1:Fields>
<soap1:Stream>dGhpcyBpcyBhIHRleHQgZmlsZQ==</soap1:Stream>
</soap1:CopyIntoItems>
</soap:Body>
</soap:Envelope>

In my case I am making a Web Service call using the plug-in therefore I'm passing a string which contains the SOAP envelope and one of the fields (Stream) in the envelope is the content of the file. That said, since I'm sending a SOAP envelope my headers are:

="Content-Type"
="application/soap+xml; charset=utf-8"

and my SOAP envelope looks like this

<soap:Envelope xmlns:soap='www.w3.org/.../soap-envelope' xmlns:soap1='schemas.microsoft.com/.../'>
<soap:Header/>
<soap:Body>
<soap1:CopyIntoItems>
<soap1:SourceUrl>Default</soap1:SourceUrl>
<soap1:DestinationUrls>
<soap1:string>xxxx.xxxxx.net/.../soap1:string>
</soap1:DestinationUrls>
<soap1:Fields>
<soap1:FieldInformation Type='Text' DisplayName='xxxxxx' InternalName='xxxxx' Id='22222222-2222-2222-2222-222222222222' Value='xxxxx'/>
</soap1:Fields>
<soap1:Stream>dGhpcyBpcyBhIHRleHQgZmlsZQ==</soap1:Stream>
</soap1:CopyIntoItems>
</soap:Body>
</soap:Envelope>