From a quick google search, I see several that may or may not be good:
H2Pas is a popular tool to convert C headers to Pascal. I don't know of any to actually convert C code to Pascal code though.
I am tempted to say you'll have to do a lot of it by hand one way or another.
Yeah, tried c2pas, but might as well write the program in pascal from scratch than use that. It may work for dead simple programs though.