Execution project numbers only should be available for AP Invoices creation at Invoice line level

Summary:

We have 2 types of projects.

Execution project : Execution project number starts with "E"
Funding project : Funding project number starts with "A"

When user create any Payable Invoice at invoice line level Funding Project numbers (starts with "A") should not available for selection. Only should be available Execution project number which starts with "E". Is there any possibility to restrict the Funding project number starts with "A".