VBA acept data only if Vlookup of offset value equals hlookup of the offset value, then lock cell, if not remove

[Fritz S]

Hello am Fritz
Please my final year project is 9 days left to submit and i still have an issue in VBA

On Sheet1 Column D11:D609 different students have to enter their Student ID to select a project.
The Projects numbers are are on sheet1 Column O11:O609

The Student IDs are on sheet4 Column C7:C512 their corresponding departments are in Column F7:F512
The Projects Are on sheet4 Column N7:N100
For each project, there are specific departments that can select it, not just anyone from any department
The departments that can select a specific project are listed in the same row as the project number in array P7:Y106

To select a project on sheet4, you enter just your student ID in any cell in Sheet1 column D11:D609

If the VLookup of your Student ID in sheet4 C7:F512 offset (0,3), that is your department, if this department is also an element of HLookup of the Project number's departments in Sheet 4 then, enter value and lock cell otherwise remove value MsgBox "You cannot select this project"

Thank you. Attched is the excel file