We have requested the company to add script tag to reference our own JavaScript which we have developed, packaged in SCORM Format as part of a training course material, and uploaded to the portal web space using Course Publisher. The JS file was then accessible from the source of the main page.
The company then agreed to add this script reference, and we were able to load all other required scripts and CSS using Dynamic Script Loading, and it is now being loaded with every page refresh. This has enabled us to customize the portal using client script and CSS.
We managed to load jQuery Plugins for adding Hijri Calendar support using Date Picker and Calendar Controls. We were able to convert, in both directions, between any existing Gregorian Date Filed and the newly added Hijri Date Field for Display and Data Entry.
For more details check the following videos: