Regex formatting Question

I am looking to input a text field for customers. I want them to be able to put in numbers with decimals, between a certain target value and 100. In this case, lets say 3. The issue i am running into, is that docusign is recognizing only the 1st digit in the sequence, and so while answers like 35, 62 and 90 are accepted, answers like 12 and 29 are not. I would like docusign to recognize double digit numbers, while still adhering to the lower end threshold.
Here is the formula i currently have, any advice would be greatly appreciated. 
^(?:[3-9]?\d(\.\d{1,2})?|100(\.00)?)$