[R] special question on regression

[Johannes Radinger]

Hello R-people!

I have a general statistical question about regressions. I just want  
to describe my case:

I have got a dataset of around 150 observations and 1 dependent and 2  
independent variables.
The dependent variable is of metric nature (in my case meters in a  
range from around 0.5-10000 m). The first independent is also metric  
(in mm ranging from 50-700 mm) and it is assumed to be in a linear  
relation with the dependend one. So that is not a problem at all to  
do a typicall linear regression on that.

No there is the second independent variable. This is also of metric  
nature and gives information on time (ranging from 1 day to 800 days)  
but here sometimes is this variable not exactly clear, I know for  
example a range (1-2 days) or less than x days etc. So my dataset  
could look like this:

measured dependent variable in days:
1
15
7-9
<2
<9
24
4
4-7

So my question: Is there a general method to include such types of  
variables into a regression analysis?

Secondly I assume that there is not a linear relation given, it is  
more of a logarithmic nature so that the influence of the time on the  
dependent variable decreases with increasing size.

So in short my questions:
* How can I use variable values like <5 or 4-5 in a regression
* Is it possible to combine the linear relationship with a  
logarithmic one in a multiple regression
*How can that be done in R, are there any special packages you'd  
recommend?

Thank you very much

best regards
Johannes