Which of the following sentence constructions is correct?

• Would that এর ব্যবহার: 
- Sentence এর শুরুতে would that থাকলে subject এর পরে could বসে এবং প্রদত্ত verb এর present form বসে। 
- অবাস্তব ইচ্ছা বা সম্ভাবনা প্রকাশে Would that ব্যবহৃত হয়। 

Examples: 
- Would that I could go back in time and undo my mistakes.
- Would that she could see how much I care for her. 

Complete Sentence - Would that the weather could be sunny for our picnic. 

Source: Advanced Learner's Communicative English by Chowdhury & Hossain.