The "Target:" line that you see contains the command that windows uses
to run your program. It is this line that may accept a parameter
telling the program which file to run when it starts up. Try just
adding the name of the file (including it's directory path and
extension) after the existing command with a space between.

For example, if the existing command is:

"C:\program files\mybrowser\mybrowser.exe"

and the file you want to start automatically is:

"C:\mydirectory\mypage.html"

Then the target line should look like:

"C:\program files\mybrowser\mybrowser.exe" "C:\mydirectory\mypage.html"

(that's all one line with a space after exe" ... it might wrap around
in your reader)

The quotes are necessary if there are embedded spaces in the command
or the parameter.

I'm guessing here that your program will accept a parameter in this
format. Some programs might require a forward slash or other character
before the parameter. Your application documentation or help file
might tell you. If you tell us what actual program you are using,
someone may know the specific parameter format for that case.