Extract Numbers only from a cell

This formula will extract all the numbers from a cell (string)

=SUMPRODUCT(MID(0&A4,LARGE(INDEX(ISNUMBER(–MID(A4,ROW($1:$25),1))* ROW($1:$25),0),ROW($1:$25))+1,1)*10^ROW($1:$25)/10)

The 2 cells refs in bold will need to change to the cell you wish to extract numbers from.