Factorizing an expression into a function of one parameter symbolic toolbox

Say I have some general symbolic expression which is a function of many symbolic variables a,b,c,d,e,f... etc. e.g. FF = cos(a)*(sin(a)*cos(b)*c + cos(d)*cos(e)*f) + cos(f)*e + ...

Is there a good tool to express this in the form FF = F_1(a) * F_1(b,c,d,e,f) + F_2(a) * F_2(b,c,d,e,f)) + ... i.e. a series of functions of one parameter (a) and coefficients which are constant with respect to this factor?

Naturally the reason to do this is for integration, the integral over a is not something matlab can do analytically but it is fairly simple to introduce a value for this integral depending on the form of these functions, if it can be expressed in this form of course.