Embedding a Link in Posts, Emails and Documents

[Charlie Programmer]

Hello all,

I have just written my first web site and I have a link that goes to a
particular item with a parameter as in www.domain.com/?a=L123AB I want
people to be able to put the link wherever they want to give others
one-click access to that item on my site. I can think of 3 contexts:

1. Put the link in a post to a discussion group (such as this one.)

2. Email the link to someone who can then click the link in the email.

3. Include the link in a word processed document that people can then
click on.

Ideally the link would display as arbitrary text but second best is if
the display is the link itself.

How do I get the example URL www.domain.com/?a=L123AB to display as
SEE ITEM or as itself in these contexts?

Thanks for any help,

Charlie