Add a value entered in a cell to the existing value in same cell in another Sheet

Hello

I have a complex Running Sales report Sheet (with multiple fields) with two worksheet viz. WEEKLY_REPORT and RUNNING_REPORT.

I am using a Userform to enter Weekly Sales Values in WEEKLY_REPORT sheet which is working fine. I am trying to figure out a way to add the values added to the Weekly_Report sheet to the Running_Report Sheet (exactly same cell) in a cumulative way i.e. I want to maintain a running total of multiple weeks in the Running_Report sheet and add a new value to the existing value every week.

Can anyone suggest a way to achieve this with or without VBA ?

I am attaching a sample sheet for reference. Please note that I have not added the Userform and the code in the attached sample sheet.

Thanks in advance

Cheers
V