InstallShield LE - relative paths for files in solution folder That are not part of content files

I am creating a setup from InstallShield LE. My setup contains files that are in solution folder but not part of content files. E.g. My solution Folder is C:\MyProject\Project1\Dev And Files I want to add too InstallShield LE setup is at: C:\MyProject\CommonFiles\Libraries So the path C:\MyProject is common and some developer can have this path as D:\MyProject. So I want to add relative path for C:\MyProject\CommonFiles\Libraries (Something like ....\CommonFiles\Libraries). I tried editing .isl file of InstallShield LE but its not working. There is a table named "ISPathVariable" but I am not sure that about how to use it for relative path. Anyone got any ideas?

I finally got the issue resolved by manually changing the .isl file. the steps followed are as below:

1. Add the files from the required location (say C:\MyProject\CommonFiles\Libraries) in InstallShield project
2. Close the Installshield Project
3. open the .isl file in Notapad
4. Add a path variable. To add the path variable, the path variable "ISProjectFolder" gives the path to .isl file. In my cas the .islFile is at location C:\MyProject\Project1\Dev\InstallShieldSetup and CommonFiles location is C:\MyProject\CommonFiles\Libraries so to access common libraries, we need to go 2 level up from InstallShieldSetup folder.
5. So I added my new path variable CommonPath as CommonPath<ISProjectFolder>....\CommonFiles2
6. And use this CommonPath variable in the tag (where files added in InstallShield are mentioned) as <LumedxCommonPath>\Libraries\File1.dll where the hardcoded path C:\MyProject\CommonFiles\Libraries\File1.dll is mentioned.
7. Save the .isl file and reload the InstallShield project.