• As you mentioned, you need an .ogs file and a custom button. And then associate this .ogs with the button settings. The draw back is you should also share this .ogs file.



• Make a button by:
  
  Add a test on worksheet, right-click and select Programming Control.
  
  
  
  And then call the c function
  
  



• Beside buttons, you can also turn you .c functions into an X-Function, and shared this X-Function with others. X-Functions can easily run from command window or custom menu item. It just need to compile once, and it doesn't need to attached with an OPJ. Please look at "Help -> Programming -> X-Function" to see how to create one.

%P=System.Path.Program$;
%Z=OriginC\System\rnahl\ImportSpecial\MicrocalDSC\MicroCalDSC.c;
if(run.loadOC(%P%Z)!=0)
{
     ty -q Cannot Load Origin Support File MicroCalDSC.c;
     ty -b;
}
 else
{
     ty -q Loading Origin Support File MicroCalDSC.c;
     MassNormalizeMCVPDSC();
};