Sort data into multiple rows

Hi,
First post so thanks in advance for any help on this.

I'm trying to merge 2 spreadsheets togeather but befor I can do this I need to resolve the following issue - my Excel worksheet has 2 columns with data that looks like this
Value1 X1,X2,X5
I need it to change to this
Value1 X1
Value1 X2
Value1 X5

DAC