I don't think you have to worry about that with CCM. I can take up to 10 (that is what I have my line configured for) from a single line appearance on 7960 phone.
To answer your question, no you cannot. But you don't need to.
Go to the line on the phone in CCMAdmin and scroll down until you get to
Multiple Call / Call Waiting Settings
These control how many calls can come into the phone and what the threshold is for it to consider itself busy. I am pretty sure that in 4.0 and higher the max number of calls a single line can have is 254.
It is what it is!!
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A+, Net+, I-Net+, Certified Web Master, MCP, MCSA, MCSE, CCNA, CCDA, and few others (I got bored one day)