a single label where multiple fields follow

Hi

I would like to get some opinions on the best practise for assigning <label for""> to inputs where there are multiple inputs for example for telephone numbers, sort codes, credit card numbers. I have had a look at the friends of ed book "Web Accessibility" and my understanding is that the title attribute should be used for the additional fields and <th> where possible.

Picking examples from websites, what would the best approach be (assume the fields cannot be changed to a single field)

For a credit card entry that is split across 4 fields, what would be placed in the following titles where below there is "????"
<label for"creditcard">credit card number</label><input type="text" id ="creditcard" title="first 4 digits">&nbsp;<input type="text" title="????">&nbsp;<input type="text" title="????">&nbsp;<input type="text"  title="????">

For a telephone number, would this be acceptable ie the label to the first field that has a title and the sceond field with a title. 
<label for"telephone">telephone number</label><input type="text" id ="telephone" title="area code">&nbsp;<input type="text" title="local number">

For a bank sort code
<label for"sortcode">sort code</label><input type="text" id ="sortcode" title="first 2 digits">&nbsp;<input type="text" title="middle 2 digits">&nbsp;<input type="text" title="last 2 digits">

Any further guidence would be appreciated

Thanks

Antony