Copy Specific Cells in All Active Worksheets to Summary Sheet

Hi,
Completely new to VBA so all help much appreciated. I am attempting to write a macro to copy specific cells (ie B2, B4, G6, H22) from all active worksheets in a workbook (the number of worksheets will increase through time) and paste the values into a summary sheet called ‘Register’ in the same workbook. I would like the macro to delete all entries in the Register initially then copy the values from all current worksheets.
I have tried a few that I found online but cannot get them to work.
All help is much appreciated.

Example spreadsheet now attached.