How do I create a transparent background without the white background showing?

I would very much appreciate help with creating a signature only seen (signed in black ink,) with a transparent background. I'm a small business owner with employee ID cards. The card background has lines and a few images that I would like the signature to go over with the background being seen as is. When I try importing or copy & paste a gif signature from one of my employee’s onto the business card, the white background still shows. I am using CorelDRAW Graphics Suite X4. 

If someone would be kind enough to explain to me in "baby talk", i.e. step by step, how I can accomplish this, it would be greatly appreciated.

 

Much thanks in advance

TRTI