Fonts for embedded lighthouse

[goli]

Where should i put the fonts files that i will be able to use them from the qt program?
i put those files(etc:helvatica) in /.../lighthouse/lib on the device but the program does not find this font, and use the default font from /usr/share/fonts....

[goli]

I create a fontdir file in /…/lighthouse/lib :
@Helvetica helvetica_100_50.qpf FT n 50 100 s
Helvetica helvetica_100_50i.qpf FT y 75 100 s
Helvetica helvetica_100_75.qpf FT n 50 100 s
Helvetica helvetica_100_75i.qpf FT y 75 100 s
Helvetica helvetica_120_50.qpf FT n 50 120 s
Helvetica helvetica_120_50i.qpf FT y 75 120 s
Helvetica helvetica_120_75.qpf FT n 50 120 s
Helvetica helvetica_120_75i.qpf FT y 75 120 s
Helvetica helvetica_140_50.qpf FT n 50 140 s
Helvetica helvetica_140_50i.qpf FT y 75 140 s
Helvetica helvetica_140_75.qpf FT n 50 140 s
Helvetica helvetica_140_75i.qpf FT y 75 140 s
Helvetica helvetica_180_50.qpf FT n 50 180 s
Helvetica helvetica_180_50i.qpf FT y 75 180 s
Helvetica helvetica_180_75.qpf FT n 50 180 s
Helvetica helvetica_180_75i.qpf FT y 75 180 s
Helvetica helvetica_240_50.qpf FT n 50 240 s
Helvetica helvetica_240_50i.qpf FT y 75 240 s
Helvetica helvetica_240_75.qpf FT n 50 240 s
Helvetica helvetica_240_75i.qpf FT y 75 240 s
Helvetica helvetica_80_50.qpf FT n 50 80 s
Helvetica helvetica_80_50i.qpf FT y 75 80 s
Helvetica helvetica_80_75.qpf FT n 50 80 s
Helvetica helvetica_80_75i.qpf FT y 75 80 s@

all the qpf file are in the same directory, but i got the same result...