Hi,
this is the way i did it and it worked for me:
app.openDoc({cPath: "fileToBeOpened.pdf", oDoc: this, sFS: "", bHidden: 0, bUseConv: 0});
This is out of the documentation 'Acrobat JavaScript Reference':
cPath:A device-independent path to the document to be opened. The path can relative to oDoc, if passed. The target document must be accessible in the default file system. NOTE:When cFS is set to "CHTTP", the cPath string should be escaped, perhaps using the core JavaScript global function encodeURI().
oDoc:(optional) A Doc Object to use as a base to resolve a relative cPath. Must be accessible in the default file system.
cFS: (optional, version 7.0) A string that specifies the source file system name. Two values are supported: "" (the empty string) representing the default file system and "CHTTP". The default is the default file system. This parameter is only relevant if the web server supports WebDAV.
bHidden:(optional, version 7.0) A boolean, which if true, opens the PDF file with its window hidden. The default is false.
bUseConv: (optional, version 7.0) This parameter is used when cPath references a non-PDF file. The bUseConv is a boolean, which if true, the method will try to convert the non-PDF file to a PDF document. The default for this parameter is false.
NOTE:(Security version 7.0) bUseConv can only be set to true during console and batch events.
For the file name you should concatenate variables and static strings like this:
var sUserInput=[user entered number from num field here];
var sFileName=("/c/BC06-" + sUserInput + ".pdf");
app.openDoc({cPath: sFileName, oDoc: this, sFS: "", bHidden: 0, bUseConv: 0});
Let me know.
Valerio