unable to open local pdf file via custom url protocol

I have created a protocol handler to open acrobat reader dc . So as soon as a link in my webapp is clicked I am trying to launch acrobat with the local pdf file .

mypdf:c:testform.pdf this is the url I hit

This is the command in the protocol handler given :
"acrobat.exe" /A "zoom=1000" "%1"

But is says the "there was an error opening document the file name or volume label syntax is incorrect.

when replacing %1 with c:testform.pdf in registry acrobat reader opens the file with no problems.

Source: Windows Questions