Campaign Pricing

Hi SAP Gurus,

I need to assign a specific discount to the target group in a campaign. In this scenario, which usage type should I take namely PR-Pricing or BO-Rebate or FG-Free Goods or CD-Campaign Determination.

If I take Campaign Determination(CD), I am not able to create a condition record. Also the Group Condition Maintenance is seen in Web UI, but I am not able to assign a discounted price either in currency or percentage.

Kindly help me out.