i know this thread is rly old but i have a rly good simple solution, here it is:
1. make a batch file with a relative path inside it.
2. get your icon in ico format (
here's an online converter)
3. Download
this program
4. open the program and choose the batch file you made in step one in the first field
5. check the "invisible application" radio button
6. go to the 3rd tab and brows for the ico file you made and finaly press compile.
once all is said and done you can delet the batch and ico files and as long the exe file stays in the same place relative to the program its luanching, it will always work.