Most PCI firewire cards supporting a firewire header usually have an internal firewire interface. There isn't a popular standard for firewire header connectors other than firewire itself. Firewire headers which don't have a firewire connector usually have customised connectors specific to a certain motherboard.
So unfortunately, unless your firewire header has a firewire connector, there's not much hope.
|Desktop PC| |Macbook Air 13" (Mid 2013)|
|Windows 8.1 Pro (x64)| |AMD FX 4100 Black Edition 3.6 GHz @ 4.0 GHz OC| |Arctic Cooling Freezer 13 PRO| |Gigabyte Nvidia GeForce GTX 560 Super Overclock 1GB| |ASUS M5A78L-M/USB3 Motherboard| |Samsung 840 Pro 256GB SSD SATA III HDD| |Kingston HyperX 8GB PC3-14900 DDR3-1866| |OCZ ModXStream Pro 700W Modular PSU| |NZXT Vulcan Micro ATX Case|