Assign a relative value from a cyclic range?

Ok, i have a very specific and (i assume) fairly complex question:

In one sheet i have a data range of 18 time stamps (numeric value of minutes)

Ie:
F10 12
F11 13
F12 16
..//..
F18 12

In Cell B4 (of current sheet)i have the starting time
Ie:
B4 09:00

In Cell B5 (of current sheet)i have the start position (1-18) of that group, that represents
the positions of the data range in the other sheet (above)

What i do in current sheet is to show a relative timetable

With this formula in a colume (1-18)
=B4+TIME(0;Banan!F10;0)
=B4+TIME(0;(Banan!F10+Banan!F11);0)
=B4+TIME(0;(Banan!F10+Banan!F11+Banan!F12);0)
etc....

This ONLY works if i start on position 1 in the referalsheet (F10)

What i want to be done is to use ther current sheets B5 value to set
starting point in the data range and then cycle through all the cells.


Ie (This does obviusly not work... ):
=B4+TIME(0;Banan!)(x+b5));0)
=B4+TIME(0;(Banan!(x+b5)+Banan!(y+b5);0)
=B4+TIME(0;(Banan!(x+b5+Banan!(y+b5)+Banan!(z+b5);0)

Etc. so that if the cycle starts at the referal sheets F14 it should end at F13


Finally the question:

How do i acomplish that?


//Micael Magnusson