Format Hierarchical Pivot Table x-axis labels

[TamirBasin]

https://drive.google.com/open?id=0Bzz1wn6UL_b6NzdEUWdhTEkwdUE

In thePivot chart above, there are 3 levels of labels, coming from the Pivot Table.
[TABLE="width: 1"]
<tbody>[TR]
[TD] 1st Level:[/TD]
[TD] : Month's names[/TD]
[/TR]
[TR]
[TD] 2nd level: [/TD]
[TD] Promotion / No Promotion[/TD]
[/TR]
[TR]
[TD] 3rd Level:[/TD]
[TD] Names of Sales Promotions[/TD]
[/TR]
</tbody>[/TABLE]


I need to create an emphasis on the Promotion's names (where it shows the number of the years).
Meaning, some of the values should be bold and some not.

Can it be done?

Thank you,

Tamir