To extend a proprietary system with a custom form typically costs thousands of dollars and plenty of time. If you do spend the money and pay for a custom form, typically, you won't own the license on the form you paid for, and thus you can't share it with a colleague who might also want use of the same form.
OSCAR contains a number of programatic interfaces and template examples which allows the end user an opportunity to extend the system with additional forms. These extensions can be made using simple web design paradigms which are easy to learn.
For example, if you wish to create a form that has a check box on it, you would use a command such as:
<div style="position: absolute; left:90px; top:30px;">
<input type="checkbox" name="thischeckbox1">
If you wish to create a form that has a text input box, then the command is similar to:
<div style="position: absolute; left:90px; top:50px;">
style="height: 83px; width: 289px;"
OSCAR users have created an excellent tutorial to get you started with building your own forms. This tutorial can be found on the OSCAR Canada Users Society website.