1.Which software can be used?
You should choose a powerful software if you want to convert wmf to pdf file and set the page height for pdf file.Not only the page height, such as width,producer,creator,title,keywords,etc.the software will do.
Maybe you have never heard of HTML Converter command line.It is an application of HTML Converter which allows you to create previews or thumbnails of web pages in a number of different formats, such as TIF, TIFF, JPG, JPEG, GIF, PNG, BMP, PCX, TGA, JP2 (JPEG2000), PNM, etc. It also allows you to convert web pages to PDF, PS (postscript), WMF, EMF vector formats.The command line application is very convenient if you have ever benefited from it.Because it only contain called program,source file and target file.The whole process will cost you only a few minutes.
In addition,HTML Converter command line application can be called from within ASP, VB, VC, Delphi, BCB, Java, .NET and COM+ etc. program languages. It uses advanced techniques to allow efficient asynchronous multithreaded operations. It will be compatible with the system in your computer.
2.How to set the page height when converting wmf to pdf?
First you need to run cmd.exe program in which you can input DOS commands.Just click 
button and click “run” in the menu,then input “cmd” in the popup dialog box.Click “OK” button.
Second input the command line.The main structure of the command line is
“htmltools.exe” –height value “input.wmf” output.pdf
htmltools.exe is the executable file in HTML Converter command line,which should be called in the conversion of wmf to pdf.
-height value is the page height of pdf file,which you can set any value yourself.
input.wmf is the source file which is stored in your computer.
output.pdf is the target file which you want to get.
If you don’t understand the command line above,you can see the following example for your better understanding.
"C:\Documents and Settings\admin\Local Settings\Temp\htmltools\htmltools.exe" -height 30 "C:\Program Files\docPrint Pro v5.0\blank.wmf" blank.pdf
It can be divided into four parts—htmltools.exe,parameter,wmf file and pdf file.
"C:\Documents and Settings\admin\Local Settings\Temp\htmltools\htmltools.exe" is the path of htmltools.exe.
-height 30 is the page height of target file.
"C:\Program Files\docPrint Pro v5.0\blank.wmf" is the path of source file.
blank.pdf is the name of target file.
NOTE:1.You can see the paths of htmltools.exe and source file are too long to input or remember.There are some other way to save your precise time.You can copy the path of the file and right click your mouse in cmd.exe dialog box,which means “paste”.You’d better enclose the path with double quotes.The easiest way is dragging the file you need into cmd.exe dialog directly.
2.You can specify the name and directory for target file in command line.If not,the source file will be converted to pdf file and saved in current directory with the same name of source file.
Third,you can find the target file in some location of your computer.