help graphing imported data

I am importing data from a serial port
each cell is filled with a number (just what i wanted) . however the number is followed by a space then g or space then g?.


The number I want and need to graph but the g or g? makes the chart function not recognize the cell as a numerical data value.

The only way I can get an apropriate graph is to delete one by one the g or g? in each cell

The data stream averages about 250 cells there must be a easy way to remove all of them with a formula or filter or somthing
I do not know anything about excel or spread sheets in general and have not been able to find a solution.


Any Help???

Thanks
Dan