Load BW data - sum key figures

I would like to load Begining Inventory value from BW cube but the 0COPC_C07 BW cube has 8 key figures that it need to be summed to find the beg. inventory value.

Example:

BW cube key figures

...DIF_M_F    ...DIF_M_V    ...DIF_S_F    ...DIF_S_V     0PERVAL_F        0PERVAL_V    ...DIF_M_F    0PRCDIF_M_V    0PRCDIF_S_F    ...DIF_S_V

     0,00         0,00         0,00         0,00         0,00    1.457.282,28         0,00     72.180,54          0,00     6.865,92

     0,00         0,00         0,00         0,00         0,00    -0,01         0,00          0,01          0,00         0,02

The total 1.536.328,76 need to be saved in SIGNEDATA in BPC.

Is it possivble? Or I need to have in BW a keyfigure with the total?