How to Pass byte[] from Excel vba to web service -

i want pass byte[] excel vba web service.

below code convert file byte[].

dim bytfile() byte bytfile = getfilebytes("c:\test.doc") 

below code used call webservice. bytfile parameter

dim xmlhttp object: set xmlhttp = createobject("microsoft.xmlhttp") xmlhttp.open "post", service + "/passexceldata", false xmlhttp.setrequestheader "content-type", "application/x-www-form-urlencoded" xmlhttp.send "filebyte=" & bytfile  

but not able pass webservice. getting error @ last line. want possible? if not, way can achieve this?

i have tried below code

function filetostr(byval strfile string) string  dim hfile long  hfile = freefile  open strfile input #hfile  filetostr = input$(lof(hfile), hfile)  close #hfile end function 

and called as:

xmlhttp.send "filebyte=" & filetostr(file path). 

but returned below error:

you can't append byte array & operator. text of file using use function

function filetostr(byval strfile string) string      dim hfile long      hfile = freefile      open strfile input #hfile      filetostr = input$(lof(hfile), hfile)      close #hfile  end function 

and xmlhttp.send "filebyte=" & filetostr("path file")

you can comment out getfilebytes line